European Heart Journal - Case Reports, Dec 7, 2021
BackgroundIn 2018, the European Society of Cardiology published two consensus documents on takots... more BackgroundIn 2018, the European Society of Cardiology published two consensus documents on takotsubo syndrome (TTS), which include the current consensus on nomenclature, diagnosis, management, and complications. However, little is mentioned on the association with complete heart block (CHB), except that ‘AV block [occurs in] 2.9% of cases’. Complete heart block is a recognized rare association of TTS, but causation is often unclear. Does CHB trigger TTS or vice-versa? Here, we present a case of TTS associated with CHB.Case summaryAn 89-year-old woman presented with a transient loss of consciousness, acute chest pain, and dyspnoea. A few days prior to this her daughter died suddenly of a myocardial infarction. On presentation, troponin levels were elevated, the electrocardiogram showed CHB with a broad QRS and an echo showed apical akinesis and ballooning. Angiographic investigation excluded significant coronary artery disease. A dual-chamber pacemaker was implanted after a brief period of temporary pacing. Ventricular function normalized during follow-up and her underlying rhythm remained CHB.DiscussionTakotsubo syndrome may be triggered by both emotional and physical stressors. Complete heart block is recognized association, but causation is often unclear. In our case, a clear emotional trigger was identified suggesting the TTS may have precipitated CHB not vice versa.
PURPOSE Cardiac resynchronization therapy (CRT) reduces ventricular activation times and electric... more PURPOSE Cardiac resynchronization therapy (CRT) reduces ventricular activation times and electrical dyssynchrony, however the effect on repolarization is unclear. In this study, we sought to investigate the effect of CRT and left ventricular (LV) remodeling on dispersion of repolarization using electrocardiographic imaging (ECGi). METHODS 11 patients with heart failure and electrical dyssynchrony underwent ECGi 1-day and 6-months post CRT. Reconstructed epicardial electrograms were used to create maps of activation time, repolarization time (RT) and activation recovery intervals (ARI) and calculate measures of RT, ARI and their dispersion. ARI was corrected for heart rate (cARI). RESULTS Compared to baseline rhythm, LV cARI dispersion was significantly higher at 6 months (28.2 ± 7.7 vs 36.4 ± 7.2 ms; P = 0.03) but not after 1 day (28.2 ± 7.7 vs 34.4 ± 6.8 ms; P = 0.12). There were no significant differences from baseline to CRT for mean LV cARI or RT metrics. Significant LV remodeling (>15% reduction in end-systolic volume) was an independent predictor of increase in LV cARI dispersion (P = 0.04) and there was a moderate correlation between the degree of LV remodeling and the relative increase in LV cARI dispersion (R = -0.49) though this was not statistically significant (P = 0.12). CONCLUSION CRT increases LV cARI dispersion, but this change was not fully apparent until 6 months post implant. The effects of CRT on LV cARI dispersion appeared to be dependent on LV reverse remodeling, which is in keeping with evidence that the risk of ventricular arrhythmia after CRT is higher in non-responders compared to responders.
This chapter gives an overview of re-entry tachycardias dependent on the AV node and describes th... more This chapter gives an overview of re-entry tachycardias dependent on the AV node and describes the approach to partial (AVNRT) and complete (AV node) catheter ablation.
technique using 10-11F mechanical dilator sheats for passive fixation atrial lead and ventricular... more technique using 10-11F mechanical dilator sheats for passive fixation atrial lead and ventricular dual coil active fixation lead. LV lead was armed with non-autolocking stylet, disanchored with just 4 counterclockwise rotations and simply retrieved with manual traction. Procedure was well tolerated without any complication. After 21 days of targeted anthibiotic therapy, patient was right-sided reimplanted with CRT-D and a new Attain Stability Lead in the same PL branch of CS of former one. Conclusions: in our experience, Medtronic Attain Stability active fixation LV lead showed to be safely and effectively extracted, aven 19 months after implantation, as never reported before in literature.
Background: The decision to implant a cardiac resynchronization therapy (CRT) device and particul... more Background: The decision to implant a cardiac resynchronization therapy (CRT) device and particularly a CRT defibrillator may be challenging in older patients, due to the difficulty in evaluating their life expectancy. Nonetheless, CRT in the elderly is of major relevance as heart failure prevalence increases with age. Purpose: To assess 12-months survival after CRT implantation in patients aged 75 years and to identify predictors of 12-months mortality. Methods: We prospectively analyzed clinical, instrumental data and survival of 75 years-old patients who received a CRT device in the CRT-MORE registry from 2011 to 2014. The primary endpoint was total mortality at 12 month follow-up. Adverse events for the analysis of clinical outcome comprised nonfatal HF events requiring hospitalization. Clinical Composite Score (CCS) was also evaluated at 12 month follow-up. Results: We included 345 patients (mean age 80 years, 30% male, 50% ischemic, 78% with defibrillator backup). After 12 months, 20 patients had at least one HF hospitalization, 30 died and 4 had both events. The resulting survival rate at 12months was 90%. 43% of the pts displayed an improvement in their CCS at 12 months, 37% were classified as unchanged and the remaining 20% as worsened. At multivariate Cox regression analysis adjusted for baseline confounders, age>80 years [HR¼2.45; 95%CI:1.19-5.05; p¼0.016], chronic obstructive pulmonary disease [HR¼2.88; 1.47-5.65; p¼0.0022] and impaired renal function [HR¼2.95; 1.45-5.97; p¼0.0029] remained associated with death. Then, we gathered all factors into a mortality score (i.e. the number of factors): 0 (very low risk; 99 pts-28.7%, survival rate 98%), 1 (low risk; 143 pts-41.5%, survival rate 94.4%), 2 (intermediate risk; 86 pts-24.9%¸survival rate 80.2%), 3 (high risk; 17 pts-4.9%; survival rate 58.8%). In comparison with patients with very low to low risk profile, the time to death was significantly shorter in patients with an intermediate to a high risk profile (log-rank test, HR¼6.24; 2.95-13.21; p<0.0001). Pts with accumulated risk factors (RF) displayed a trend toward lower response at 12 months as assessed by CCS (33.7% of pts with 2 or 3 RF vs 46.3% of pts with none or 1 RFs improved their status, p¼0.203) and higher rate of hospitalizations for HF (9.7% vs 5.8%, p¼0.246). Conclusion: All-cause mortality was considerably higher in the group of elderly patients with accumulated risk factors. A proper characterization of baseline parameters can be helpful for the evaluation and risk stratification of these patients prior to making a decision of implanting a CRT-P or CRT-D device.
The wearable cardioverter-defibrillator, WCD; LifeVest is a treatment option for patients at high... more The wearable cardioverter-defibrillator, WCD; LifeVest is a treatment option for patients at high risk for VT/VF, either in whom this risk may be temporarily or in whom an ICD implantation is currently not possible. Methods: Retrospective registry of patients in Austria who received a WCD 2009-2016. Results: 451 Austrian patients (59614 years; 24% female) received a WCD. Main indications were: Newly diagnosed severe cardiomyopathy (21%), recent myocardial infarction (20%), ischemic cardiomyopathy with recent PCI (14%), delayed ICD implantation (12%), acute myocarditis (10%), ICD-associated infection (10%). Left ventricular EF was 33614%, median CHA2DS2VASc-Score 3 (2-5). 48% of patients had VT/VF before the WCD period. The median WCD duration was 48 (1-436) days. There was no difference in WCD compliance between patients wearing the WCD <60 days vs. >60 days (23 (3-24) h/day vs. 22 (1-24) h/day; n.s.). 11 patients (2.4%) received adequate WCD shocks for VT/VF. Two (0.4%) inadequate shocks occurred. Only 55% of all 451 patients required ICD implantation after the WCD. Of the 45 patients with myocarditis, only eight patients (22%) required an ICD. Conclusion: The WCD is an effective treatment option in patients at high risk for VT/ VF and/or mandated waiting period for ICD implantation. Only 55% of patients require an ICD after the WCD.
Heart failure is a serious disease affecting about 23 million people worldwide. Cardiac resynchro... more Heart failure is a serious disease affecting about 23 million people worldwide. Cardiac resynchronization therapy is used to treat patients suffering from symptomatic heart failure. However, 30% to 50% of patients have limited clinical benefit. One of the main causes is suboptimal placement of the left ventricular lead. Pacing in areas of myocardial scar correlates with poor clinical outcomes. Therefore precise knowledge of the individual patient’s scar characteristics is critical for delivering tailored treatments capable of improving response rates. Current research methods for scar assessment either map information to an alternative non-anatomical coordinate system or they use the image coordinate system but lose critical information about scar extent and scar distribution. This paper proposes two interactive methods for visualizing relevant scar information. A 2-D slice based approach with a scar mask overlaid on a 16 segment heart model and a 3-D layered mesh visualization which allows physicians to scroll through layers of scar from endocardium to epicardium. These complementary methods enable physicians to evaluate scar location and transmurality during planning and guidance. Six physicians evaluated the proposed system by identifying target regions for lead placement. With the proposed method more target regions could be identified.
Optimum timing of pacemaker implantation following cardiac surgery is a clinical challenge. Europ... more Optimum timing of pacemaker implantation following cardiac surgery is a clinical challenge. European & American guidelines recommend observation, to assess recovery of atrioventricular block (AVB) (up to seven days) and sinus node (five days-weeks) after cardiac surgery. This study aims to determine rates of CIED implants post-surgery at a highvolume tertiary centre over three years. Implant timing, patient characteristics and outcomes at 6 months including pacemaker utilization were assessed. Methods: All cardiac operations (n=5950) were screened for CIED implantation following surgery, during the same admission, from 2015-2018. Data collection included patient, operative and device characteristics; pacing utilization and complications at 6 months. Results: 250 (4.2%) implants occurred; 232 (3.9%) for bradycardia. Advanced age, infective endocarditis, LV systolic impairment and valve surgery were independent predictors for CIED implants (p<0.0001). Relative risk (RR) of CIED implants and proportion of AVB increased with valve numbers operated (single-triple) vs. non-valve surgery: RR 5.4 (95% CI 3.9-7.6)-21.0 (11.4-38.9) CIEDs. Follow-up pacing utilization data were available in 91%. Significant utilization occurred in 82% and underutilization (<1% A and V paced) in 18%. There were no significant differences comparing utilization rates in early (≤day 5 postoperatively) vs. late implants (p=0.55). Conclusions: Multi-valve surgery has a particularly high incidence of CIED implants (14.9% double, 25.6% triple valve). Age, LV systolic impairment, endocarditis and valve surgery were independent predictors of CIED implants. Device underutilization was infrequent and uninfluenced by implant timing. Early implantation should be considered in AVB post multivalve surgery.
Heart failure affects nearly one million people in the UK. Half of these patients have normal, or... more Heart failure affects nearly one million people in the UK. Half of these patients have normal, or near normal, left ventricular ejection fraction and are classified as heart failure with preserved ejection fraction (HFpEF). Newer imaging techniques have confirmed that systolic function in HFpEF patients is not completely normal, with reduced long axis function and extensive but subtle changes on exercise. Patients are likely to be older women with a history of hypertension. Other cardiovascular risk factors, such as diabetes mellitus, atrial fibrillation and coronary artery disease are prevalent in the HFpEF population. Clinical symptoms and signs in HFpEF are often nonspecific although the primary symptoms are breathlessness, fatigue and fluid retention. There is still no single diagnostic test for HFpEF and the cornerstone in the assessment remains a thorough medical history and physical examination. The duration and extent of the symptoms are relevant and it is useful to classify patients according to the NYHA functional assessment. Physical examination should include the patient's BMI and weight, heart rate and rhythm, lying and standing blood pressure and auscultation to rule out valvular disease and pulmonary congestion. Estimating the jugular venous pressure and the presence of peripheral oedema allows assessment of the patient's volume status. Patients with heart failure should be referred to heart failure nurses and have follow-up with local cardiology services as these have both been shown to reduce mortality.
If citing, it is advised that you check and use the publisher's definitive version for pagination... more If citing, it is advised that you check and use the publisher's definitive version for pagination, volume/issue, and date of publication details. And where the final published version is provided on the Research Portal, if citing you are again advised to check the publisher's website for any subsequent corrections.
Excessive prolongation of PR interval impairs coupling of atrio-ventricular (AV) contraction, whi... more Excessive prolongation of PR interval impairs coupling of atrio-ventricular (AV) contraction, which reduces left ventricular pre-load and stroke volume, and worsens symptoms. His bundle pacing allows AV delay shortening while maintaining normal ventricular activation. HOPE-HF evaluated whether AV optimized His pacing is preferable to no-pacing, in a double-blind cross-over fashion, in patients with heart failure, left ventricular ejection fraction (LVEF) ≤40%, PR interval ≥200 ms and either QRS ≤140 ms or right bundle branch block.
Journal of Cardiovascular Electrophysiology, Jul 15, 2020
Background: Leadless pacemakers preclude the need for permanent leads to pace endocardium. Howeve... more Background: Leadless pacemakers preclude the need for permanent leads to pace endocardium. However, it is yet to be determined whether a leadless pacemaker of a similar design to those manufactured for the right ventricle (RV) fits within the left ventricle (LV) without interfering with intracardiac structures. Methods: Cardiac computed tomography scans were obtained from 30 patients indicated for cardiac resynchronisation therapy upgrade. The mitral valve annulus, chordae tendineae, papillary muscles, and LV endocardial wall were marked in the end-diastolic frame. Intracardiac structures motions were tracked through the cardiac cycle. Two pacemaker designs similar to commercially manufactured leadless systems (Abbott's Nanostim LCP and Medtronic's Micra TPS) as well as theoretical designs with calculated optimal dimensions were evaluated. Pacemakers were virtually placed across the LV endocardial surface and collisions between them and intracardiac structures were detected throughout the cycle. Results: Probability maps of LV intracardiac structures collisions on a 16 segment AHA model indicated possible placement for the Nanostim LCP, Micra TPS, and theoretical designs. Thresholding these maps at 20% chance of collision revealed only about 36% of the endocardial surface remained collision free with the deployment of Micra TPS design. The same threshold left no collision free surface in the case of the Nanostim LCP. To reach at least half of the LV endocardium, the volume of Micra TPS, which is the smaller design, needed to be decreased by 41%. Conclusion: Due to presence of intracardiac structures, placement of leadless pacemakers with dimensions similar to commercially manufactured RV systems would be limited to apical regions.
Journal of Interventional Cardiac Electrophysiology, Jun 14, 2019
Purpose It is uncertain whether right ventricular (RV) lead position in cardiac resynchronization... more Purpose It is uncertain whether right ventricular (RV) lead position in cardiac resynchronization therapy impacts response. There has been little detailed analysis of the activation patterns in RV septal pacing (RVSP), especially in the CRT population. We compare left bundle branch block (LBBB) activation patterns with RV pacing (RVP) within the same patients with further comparison between RV apical pacing (RVAP) and RVSP. Methods Body surface mapping was undertaken in 14 LBBB patients after CRT implantation. Nine patients had RVAP, 5 patients had RVSP. Activation parameters included left ventricular total activation time (LVtat), biventricular total activation time (VVtat), interventricular electrical synchronicity (VVsync), and dispersion of left ventricular activation times (LVdisp). The direction of activation wave front was also compared in each patient (wave front angle (WFA)). In silico computer modelling was applied to assess the effect of RVAP and RVSP in order to validate the clinical results.
European Heart Journal - Case Reports, Dec 7, 2021
BackgroundIn 2018, the European Society of Cardiology published two consensus documents on takots... more BackgroundIn 2018, the European Society of Cardiology published two consensus documents on takotsubo syndrome (TTS), which include the current consensus on nomenclature, diagnosis, management, and complications. However, little is mentioned on the association with complete heart block (CHB), except that ‘AV block [occurs in] 2.9% of cases’. Complete heart block is a recognized rare association of TTS, but causation is often unclear. Does CHB trigger TTS or vice-versa? Here, we present a case of TTS associated with CHB.Case summaryAn 89-year-old woman presented with a transient loss of consciousness, acute chest pain, and dyspnoea. A few days prior to this her daughter died suddenly of a myocardial infarction. On presentation, troponin levels were elevated, the electrocardiogram showed CHB with a broad QRS and an echo showed apical akinesis and ballooning. Angiographic investigation excluded significant coronary artery disease. A dual-chamber pacemaker was implanted after a brief period of temporary pacing. Ventricular function normalized during follow-up and her underlying rhythm remained CHB.DiscussionTakotsubo syndrome may be triggered by both emotional and physical stressors. Complete heart block is recognized association, but causation is often unclear. In our case, a clear emotional trigger was identified suggesting the TTS may have precipitated CHB not vice versa.
PURPOSE Cardiac resynchronization therapy (CRT) reduces ventricular activation times and electric... more PURPOSE Cardiac resynchronization therapy (CRT) reduces ventricular activation times and electrical dyssynchrony, however the effect on repolarization is unclear. In this study, we sought to investigate the effect of CRT and left ventricular (LV) remodeling on dispersion of repolarization using electrocardiographic imaging (ECGi). METHODS 11 patients with heart failure and electrical dyssynchrony underwent ECGi 1-day and 6-months post CRT. Reconstructed epicardial electrograms were used to create maps of activation time, repolarization time (RT) and activation recovery intervals (ARI) and calculate measures of RT, ARI and their dispersion. ARI was corrected for heart rate (cARI). RESULTS Compared to baseline rhythm, LV cARI dispersion was significantly higher at 6 months (28.2 ± 7.7 vs 36.4 ± 7.2 ms; P = 0.03) but not after 1 day (28.2 ± 7.7 vs 34.4 ± 6.8 ms; P = 0.12). There were no significant differences from baseline to CRT for mean LV cARI or RT metrics. Significant LV remodeling (>15% reduction in end-systolic volume) was an independent predictor of increase in LV cARI dispersion (P = 0.04) and there was a moderate correlation between the degree of LV remodeling and the relative increase in LV cARI dispersion (R = -0.49) though this was not statistically significant (P = 0.12). CONCLUSION CRT increases LV cARI dispersion, but this change was not fully apparent until 6 months post implant. The effects of CRT on LV cARI dispersion appeared to be dependent on LV reverse remodeling, which is in keeping with evidence that the risk of ventricular arrhythmia after CRT is higher in non-responders compared to responders.
This chapter gives an overview of re-entry tachycardias dependent on the AV node and describes th... more This chapter gives an overview of re-entry tachycardias dependent on the AV node and describes the approach to partial (AVNRT) and complete (AV node) catheter ablation.
technique using 10-11F mechanical dilator sheats for passive fixation atrial lead and ventricular... more technique using 10-11F mechanical dilator sheats for passive fixation atrial lead and ventricular dual coil active fixation lead. LV lead was armed with non-autolocking stylet, disanchored with just 4 counterclockwise rotations and simply retrieved with manual traction. Procedure was well tolerated without any complication. After 21 days of targeted anthibiotic therapy, patient was right-sided reimplanted with CRT-D and a new Attain Stability Lead in the same PL branch of CS of former one. Conclusions: in our experience, Medtronic Attain Stability active fixation LV lead showed to be safely and effectively extracted, aven 19 months after implantation, as never reported before in literature.
Background: The decision to implant a cardiac resynchronization therapy (CRT) device and particul... more Background: The decision to implant a cardiac resynchronization therapy (CRT) device and particularly a CRT defibrillator may be challenging in older patients, due to the difficulty in evaluating their life expectancy. Nonetheless, CRT in the elderly is of major relevance as heart failure prevalence increases with age. Purpose: To assess 12-months survival after CRT implantation in patients aged 75 years and to identify predictors of 12-months mortality. Methods: We prospectively analyzed clinical, instrumental data and survival of 75 years-old patients who received a CRT device in the CRT-MORE registry from 2011 to 2014. The primary endpoint was total mortality at 12 month follow-up. Adverse events for the analysis of clinical outcome comprised nonfatal HF events requiring hospitalization. Clinical Composite Score (CCS) was also evaluated at 12 month follow-up. Results: We included 345 patients (mean age 80 years, 30% male, 50% ischemic, 78% with defibrillator backup). After 12 months, 20 patients had at least one HF hospitalization, 30 died and 4 had both events. The resulting survival rate at 12months was 90%. 43% of the pts displayed an improvement in their CCS at 12 months, 37% were classified as unchanged and the remaining 20% as worsened. At multivariate Cox regression analysis adjusted for baseline confounders, age>80 years [HR¼2.45; 95%CI:1.19-5.05; p¼0.016], chronic obstructive pulmonary disease [HR¼2.88; 1.47-5.65; p¼0.0022] and impaired renal function [HR¼2.95; 1.45-5.97; p¼0.0029] remained associated with death. Then, we gathered all factors into a mortality score (i.e. the number of factors): 0 (very low risk; 99 pts-28.7%, survival rate 98%), 1 (low risk; 143 pts-41.5%, survival rate 94.4%), 2 (intermediate risk; 86 pts-24.9%¸survival rate 80.2%), 3 (high risk; 17 pts-4.9%; survival rate 58.8%). In comparison with patients with very low to low risk profile, the time to death was significantly shorter in patients with an intermediate to a high risk profile (log-rank test, HR¼6.24; 2.95-13.21; p<0.0001). Pts with accumulated risk factors (RF) displayed a trend toward lower response at 12 months as assessed by CCS (33.7% of pts with 2 or 3 RF vs 46.3% of pts with none or 1 RFs improved their status, p¼0.203) and higher rate of hospitalizations for HF (9.7% vs 5.8%, p¼0.246). Conclusion: All-cause mortality was considerably higher in the group of elderly patients with accumulated risk factors. A proper characterization of baseline parameters can be helpful for the evaluation and risk stratification of these patients prior to making a decision of implanting a CRT-P or CRT-D device.
The wearable cardioverter-defibrillator, WCD; LifeVest is a treatment option for patients at high... more The wearable cardioverter-defibrillator, WCD; LifeVest is a treatment option for patients at high risk for VT/VF, either in whom this risk may be temporarily or in whom an ICD implantation is currently not possible. Methods: Retrospective registry of patients in Austria who received a WCD 2009-2016. Results: 451 Austrian patients (59614 years; 24% female) received a WCD. Main indications were: Newly diagnosed severe cardiomyopathy (21%), recent myocardial infarction (20%), ischemic cardiomyopathy with recent PCI (14%), delayed ICD implantation (12%), acute myocarditis (10%), ICD-associated infection (10%). Left ventricular EF was 33614%, median CHA2DS2VASc-Score 3 (2-5). 48% of patients had VT/VF before the WCD period. The median WCD duration was 48 (1-436) days. There was no difference in WCD compliance between patients wearing the WCD <60 days vs. >60 days (23 (3-24) h/day vs. 22 (1-24) h/day; n.s.). 11 patients (2.4%) received adequate WCD shocks for VT/VF. Two (0.4%) inadequate shocks occurred. Only 55% of all 451 patients required ICD implantation after the WCD. Of the 45 patients with myocarditis, only eight patients (22%) required an ICD. Conclusion: The WCD is an effective treatment option in patients at high risk for VT/ VF and/or mandated waiting period for ICD implantation. Only 55% of patients require an ICD after the WCD.
Heart failure is a serious disease affecting about 23 million people worldwide. Cardiac resynchro... more Heart failure is a serious disease affecting about 23 million people worldwide. Cardiac resynchronization therapy is used to treat patients suffering from symptomatic heart failure. However, 30% to 50% of patients have limited clinical benefit. One of the main causes is suboptimal placement of the left ventricular lead. Pacing in areas of myocardial scar correlates with poor clinical outcomes. Therefore precise knowledge of the individual patient’s scar characteristics is critical for delivering tailored treatments capable of improving response rates. Current research methods for scar assessment either map information to an alternative non-anatomical coordinate system or they use the image coordinate system but lose critical information about scar extent and scar distribution. This paper proposes two interactive methods for visualizing relevant scar information. A 2-D slice based approach with a scar mask overlaid on a 16 segment heart model and a 3-D layered mesh visualization which allows physicians to scroll through layers of scar from endocardium to epicardium. These complementary methods enable physicians to evaluate scar location and transmurality during planning and guidance. Six physicians evaluated the proposed system by identifying target regions for lead placement. With the proposed method more target regions could be identified.
Optimum timing of pacemaker implantation following cardiac surgery is a clinical challenge. Europ... more Optimum timing of pacemaker implantation following cardiac surgery is a clinical challenge. European & American guidelines recommend observation, to assess recovery of atrioventricular block (AVB) (up to seven days) and sinus node (five days-weeks) after cardiac surgery. This study aims to determine rates of CIED implants post-surgery at a highvolume tertiary centre over three years. Implant timing, patient characteristics and outcomes at 6 months including pacemaker utilization were assessed. Methods: All cardiac operations (n=5950) were screened for CIED implantation following surgery, during the same admission, from 2015-2018. Data collection included patient, operative and device characteristics; pacing utilization and complications at 6 months. Results: 250 (4.2%) implants occurred; 232 (3.9%) for bradycardia. Advanced age, infective endocarditis, LV systolic impairment and valve surgery were independent predictors for CIED implants (p<0.0001). Relative risk (RR) of CIED implants and proportion of AVB increased with valve numbers operated (single-triple) vs. non-valve surgery: RR 5.4 (95% CI 3.9-7.6)-21.0 (11.4-38.9) CIEDs. Follow-up pacing utilization data were available in 91%. Significant utilization occurred in 82% and underutilization (<1% A and V paced) in 18%. There were no significant differences comparing utilization rates in early (≤day 5 postoperatively) vs. late implants (p=0.55). Conclusions: Multi-valve surgery has a particularly high incidence of CIED implants (14.9% double, 25.6% triple valve). Age, LV systolic impairment, endocarditis and valve surgery were independent predictors of CIED implants. Device underutilization was infrequent and uninfluenced by implant timing. Early implantation should be considered in AVB post multivalve surgery.
Heart failure affects nearly one million people in the UK. Half of these patients have normal, or... more Heart failure affects nearly one million people in the UK. Half of these patients have normal, or near normal, left ventricular ejection fraction and are classified as heart failure with preserved ejection fraction (HFpEF). Newer imaging techniques have confirmed that systolic function in HFpEF patients is not completely normal, with reduced long axis function and extensive but subtle changes on exercise. Patients are likely to be older women with a history of hypertension. Other cardiovascular risk factors, such as diabetes mellitus, atrial fibrillation and coronary artery disease are prevalent in the HFpEF population. Clinical symptoms and signs in HFpEF are often nonspecific although the primary symptoms are breathlessness, fatigue and fluid retention. There is still no single diagnostic test for HFpEF and the cornerstone in the assessment remains a thorough medical history and physical examination. The duration and extent of the symptoms are relevant and it is useful to classify patients according to the NYHA functional assessment. Physical examination should include the patient's BMI and weight, heart rate and rhythm, lying and standing blood pressure and auscultation to rule out valvular disease and pulmonary congestion. Estimating the jugular venous pressure and the presence of peripheral oedema allows assessment of the patient's volume status. Patients with heart failure should be referred to heart failure nurses and have follow-up with local cardiology services as these have both been shown to reduce mortality.
If citing, it is advised that you check and use the publisher's definitive version for pagination... more If citing, it is advised that you check and use the publisher's definitive version for pagination, volume/issue, and date of publication details. And where the final published version is provided on the Research Portal, if citing you are again advised to check the publisher's website for any subsequent corrections.
Excessive prolongation of PR interval impairs coupling of atrio-ventricular (AV) contraction, whi... more Excessive prolongation of PR interval impairs coupling of atrio-ventricular (AV) contraction, which reduces left ventricular pre-load and stroke volume, and worsens symptoms. His bundle pacing allows AV delay shortening while maintaining normal ventricular activation. HOPE-HF evaluated whether AV optimized His pacing is preferable to no-pacing, in a double-blind cross-over fashion, in patients with heart failure, left ventricular ejection fraction (LVEF) ≤40%, PR interval ≥200 ms and either QRS ≤140 ms or right bundle branch block.
Journal of Cardiovascular Electrophysiology, Jul 15, 2020
Background: Leadless pacemakers preclude the need for permanent leads to pace endocardium. Howeve... more Background: Leadless pacemakers preclude the need for permanent leads to pace endocardium. However, it is yet to be determined whether a leadless pacemaker of a similar design to those manufactured for the right ventricle (RV) fits within the left ventricle (LV) without interfering with intracardiac structures. Methods: Cardiac computed tomography scans were obtained from 30 patients indicated for cardiac resynchronisation therapy upgrade. The mitral valve annulus, chordae tendineae, papillary muscles, and LV endocardial wall were marked in the end-diastolic frame. Intracardiac structures motions were tracked through the cardiac cycle. Two pacemaker designs similar to commercially manufactured leadless systems (Abbott's Nanostim LCP and Medtronic's Micra TPS) as well as theoretical designs with calculated optimal dimensions were evaluated. Pacemakers were virtually placed across the LV endocardial surface and collisions between them and intracardiac structures were detected throughout the cycle. Results: Probability maps of LV intracardiac structures collisions on a 16 segment AHA model indicated possible placement for the Nanostim LCP, Micra TPS, and theoretical designs. Thresholding these maps at 20% chance of collision revealed only about 36% of the endocardial surface remained collision free with the deployment of Micra TPS design. The same threshold left no collision free surface in the case of the Nanostim LCP. To reach at least half of the LV endocardium, the volume of Micra TPS, which is the smaller design, needed to be decreased by 41%. Conclusion: Due to presence of intracardiac structures, placement of leadless pacemakers with dimensions similar to commercially manufactured RV systems would be limited to apical regions.
Journal of Interventional Cardiac Electrophysiology, Jun 14, 2019
Purpose It is uncertain whether right ventricular (RV) lead position in cardiac resynchronization... more Purpose It is uncertain whether right ventricular (RV) lead position in cardiac resynchronization therapy impacts response. There has been little detailed analysis of the activation patterns in RV septal pacing (RVSP), especially in the CRT population. We compare left bundle branch block (LBBB) activation patterns with RV pacing (RVP) within the same patients with further comparison between RV apical pacing (RVAP) and RVSP. Methods Body surface mapping was undertaken in 14 LBBB patients after CRT implantation. Nine patients had RVAP, 5 patients had RVSP. Activation parameters included left ventricular total activation time (LVtat), biventricular total activation time (VVtat), interventricular electrical synchronicity (VVsync), and dispersion of left ventricular activation times (LVdisp). The direction of activation wave front was also compared in each patient (wave front angle (WFA)). In silico computer modelling was applied to assess the effect of RVAP and RVSP in order to validate the clinical results.
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