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Objectives: To investigate cardiac implantable electrical device (CIED) first implants in patients with hypertrophic cardiomyopathy (HCM) in a Swedish tertiary university hospital. Design: Clinical and technical data on pacemaker, implantable cardioverter defibrillator (ICD), and cardiac resynchronization therapy (CRT) first implants performed in HCM patients at the Karolinska University Hospital from 2005 to 2016 were extracted from the Swedish Pacemaker and ICD Registry. Echocardiographic data were obtained by review of hospital recordings. Results: The number of first pacemaker implants in HCM patients was 70 (1.5% of total pacemaker implants). The mean age of HCM pacemaker patients was 71 ± 10 years. Pacemaker implants were almost uniformly distributed between genders. Dual-chamber pacemakers with or without CRT properties were prevalent (6 and 93%, respectively). The number of first ICD implants in HCM patients was 99 (5.1% of total ICD implants). HCM patients receiving an ICD were 53 ± 15 years and prevalently men (70%). Sixty-five (66%) patients were implanted for primary prevention. Dual-chamber ICDs with or without CRT were 21 and 65%, respectively. Obstructive HCM was present in 47% pacemaker patients and 25% ICD patients with available pre-implant echo. Conclusions: This retrospective registry-based study provides a picture of CIED first implants in HCM patients in a Swedish tertiary university hospital. ICDs were the most commonly implanted devices, covering 59% of CIED implants. HCM patients receiving a pacemaker or an ICD had different epidemiological and clinical profiles. [ABSTRACT FROM AUTHOR]

Relatively few data have been reported on prospective changes in global longitudinal strain ( GLS) following cardiac resynchronization therapy ( CRT), and none are available on GLS during physical exercise. We investigated the effects of CRT on GLS, assessed by speckle tracking two-dimensional (2 D) echocardiography, at rest and during exercise after a mid-term follow-up. Twenty consecutive CRT patients (45% ischaemic) were assessed prospectively by speckle tracking 2 D echocardiography before implant (at rest) and at mid-term follow-up (during rest and bicycle exercise). GLS, septum and lateral wall longitudinal strain, left ventricular ejection fraction ( LVEF), and conventional functional variables were evaluated at baseline and follow-up. All patients completed the study protocol at rest. Exercise images were available in 90% of the patients. At follow-up, GLS improved at rest from −7·1 ± 2·6% to −9·1 ± 4·5% ( P<0·01), with a further increase to −11 ± 5·1% during exercise ( P<0·001). Longitudinal strain increased at rest both in the septum and in the lateral wall, with an additional increase during exercise in the lateral wall ( P<0·05). GLS correlated with LVEF both at rest ( r = −0·55 and r = −0·91 at baseline and 3 months, respectively; P<0·05) and during exercise ( r = −0·89, P<0·05). Improvement in GLS during rest and exercise can be observed in CRT patients at mid-term follow-up and seems to correlate with changes in LVEF. GLS may be a valuable method to assess left ventricular function during rest and exercise. [ABSTRACT FROM AUTHOR]

Aims Myocardial contractile reserve (MCR) is a marker of myocardial viability. The impact of cardiac resynchronization therapy (CRT) on MCR during exercise has been little studied. Our aim was to investigate the effects of CRT on global and regional MCR by exercise echocardiography. Methods and results Twenty-seven CRT responders (56% ischaemic) were assessed by echocardiography during rest and bicycle exercise. Images were acquired during spontaneous rhythm (‘off') and active CRT (‘on'). Global MCR was expressed as the change (Δ) in left ventricular ejection fraction (LVEF) and aortic velocity-time integral (VTI) from rest to exercise. Regional MCR was expressed as the change in peak systolic tissue velocity (Sm) of the septum and lateral wall. Left ventricular ejection fraction and aortic VTI increased at ‘on' during rest and exercise, and the increase in global MCR during exercise was higher during ‘on' than ‘off' (Δ LVEF 6 ± 6 vs. 3 ± 3%; P= 0.009). Septum Sm increased during ‘on' at rest, and it was still higher during exercise (P≤ 0.01), although the absolute change from rest to exercise was similar during ‘on' and ‘off'. Lateral wall Sm did not change at rest during ‘on', but basal lateral wall MCR during exercise was higher at ‘on' than ‘off' (P= 0.036). Conclusion In CRT responders, there is a pacing-dependent increase in global MCR during exercise. The changes in regional MCR of the septum and lateral wall show different patterns. These factors may help to understand the determinants of improved exercise tolerance in CRT responders. [ABSTRACT FROM PUBLISHER]

Abstract: Background: Relatively limited and conflicting data are available on the effects of cardiac resynchronization therapy (CRT) on coronary blood flow (CBF). Aims: To investigate changes in the left anterior descending coronary artery (LAD) flow under different CRT pacing modes by means of transthoracic Doppler echocardiography (TTE). Methods: Twenty-two responders to CRT (67±11 years) with idiopathic dilated cardiomyopathy underwent TTE assessment of LAD flow and Tissue Velocity Imaging during 4 programming modes: intrinsic conduction (IC), right ventricular pacing (RV), simultaneous biventricular pacing (BVP), BVP with left ventricular (LV) pre-activation. Results: Mean coronary flow velocity (CFV) was increased by simultaneous BVP (p =0.0063 vs. IC) and BVP with LV pre-activation (p <0.0001 vs. IC; p =0.027 vs. simultaneous BVP). Peak CFV and LAD flow velocity/time integral were highest during BVP with LV pre-activation. A reduction in septal-to-lateral delay and an increase in peak systolic velocity in the basal septum were observed during simultaneous BVP and BVP with LV pre-activation. Conclusions: In CRT responders with idiopathic dilated cardiomyopathy, an increase in LAD flow, assessed by TTE, was observed during simultaneous BVP and BVP with LV pre-activation. This was associated with an improvement in regional myocardial contraction and a decrease in intraventricular dyssynchrony. [Copyright &y& Elsevier]

Abstract: Background: Haemodynamic and functional effects of cardiac resynchronization therapy (CRT) have been studied mostly at rest. CRT effects on left ventricular (LV) dyssynchrony and function during stress have not been evaluated in detail. Aims: We studied the electromechanical effects of CRT at rest and during Dobutamine stress echocardiography (DSE), during active and withheld CRT. Methods: Twenty-one responders to CRT (62±12 yr) were assessed by walking test, quality of life, and BNP with active CRT (“on”) and 2 weeks after pacing withdrawal (“off”). DSE (10 μg/kg/min) was performed both at “on” and “off” to evaluate dyssynchrony parameters, systolic and diastolic function. Results: At rest, CRT withdrawal was associated with an increased interventricular mechanical delay (IVMD, from 21±18 ms to 49±24 ms, p <0.001) and impaired intraventricular synchrony. There was a significant decrease in LV systolic function and LV filling time. Dobutamine infusion had no impact on inter- and intraventricular synchrony. During stress, there was an improvement in LV performance both at “on” and “off”. However, LV dp/dt, aortic VTI, cardiac output, mean systolic peak velocities and LV filling time during dobutamine stress were significantly greater with CRT “on”. Conclusion: In long-term responders, CRT improves LV performance both at rest and during dobutamine stress. This is attributable to an improvement in LV synchrony, which is maintained during stress. [Copyright &y& Elsevier]

Heart failure (HF) is considered as an epidemic and affects 2% of the population in the Western world. About 15 30% of patients with HF and reduced ejection fraction (HFrEF) also have prolonged QRS duration on the surface ECG, most commonly as a result of left bundle branch block (LBBB). Increased QRS duration is a marker of a dyssynchronous activation, and subsequent contraction, pattern in the left ventricle (LV). When dyssynchrony is superimposed on the failing heart it further reduced systolic function and ultimately worsens outcome. During the past 15 years several randomized controlled clinical trials have documented that resynchronization of the dyssynchronous failing heart with a biventricular pacemaker cardiac resynchronization therapy (CRT) which can restore a more synchronous activation and contraction pattern. This translates in halted or reversed disease progression and improved clinical outcome, including reduced mortality. In this review, we will discuss several aspects of CRT including mechanisms of dyssynchrony and resynchronization in the failing heart, evidence of CRT efficacy derived from clinical trials and current challenges in CRT including patient selection and optimization of therapy delivery. Last, we will discuss future perspectives including the role of CRT to prevent adverse events in patients with an indication for antibradycardia pacing, the role of leadless pacing in the CRT setting as well as a new clinical arena where dyssynchrony and resynchronization may be important. [ABSTRACT FROM AUTHOR]

ICD Lead Position and Outcome Introduction We aim to compare the acute and long-term success of defibrillation between non-apical and apical ICD lead position. Methods and Results The position of the ventricular lead was recorded by the implanting physician for 2,475 of 2,500 subjects in the Shockless IMPLant Evaluation (SIMPLE) trial, and subjects were grouped accordingly as non-apical or apical. The success of intra-operative defibrillation testing and of subsequent clinical shocks were compared. Propensity scoring was used to adjust for the impact of differences in baseline variables between these groups. There were 541 leads that were implanted at a non-apical position (21.9%). Patients implanted with a non-apical lead had a higher rate of secondary prevention indication. Non-apical location resulted in a lower mean R-wave amplitude (14.0 vs. 15.2, P < 0.001), lower mean pacing impedance (662 ohm vs. 728 ohm, P < 0.001), and higher mean pacing threshold (0.70 V vs. 0.66 V, P = 0.01). Single-coil leads and cardiac resynchronization devices were used more often in non-apical implants. The success of intra-operative defibrillation was similar between propensity score matched groups (89%). Over a mean follow-up of 3 years, there were no significant differences in the yearly rates of appropriate shock (5.5% vs. 5.4%, P = 0.98), failed appropriate first shock (0.9% vs. 1.0%, P = 0.66), or the composite of failed shock or arrhythmic death (2.8% vs. 2.3% P = 0.35) according to lead location. Conclusion We did not detect any reduction in the ICD efficacy at the time of implant or during follow-up in patients receiving a non-apical RV lead. [ABSTRACT FROM AUTHOR]

Aims Cardiac resynchronization therapy (CRT) is an effective treatment for a subset of patients with chronic heart failure. Data on the benefit of CRT in heart failure patients with previous right ventricular pacemakers or standard defibrillators are sparse. Methods and results The European (HFA, Heart Failure Association/EHRA, European Heart Rhythm Association) CRT Survey enrolled patients from 141 centres in 13 countries in Europe collecting baseline demographic, echocardiographic, clinical, and implant data, with follow-up at ∼1 year. The present analysis reports implantation data and 1 year outcomes regarding New York Heart Association (NYHA) class, global patient assessment, hospitalizations, complications, and mortality in patients undergoing de novo CRT implantations compared with those receiving an upgrade of a previously implanted device (pacemaker or implantable cardioverter–defibrillators). This analysis includes 2367 CRT implant procedures of which 692 (28%) were upgrades to CRT. Distribution of NYHA functional class and left ventricular function were similar between the groups. Procedural duration was also similar, although fluoroscopy time was shorter in the ‘upgrades’. There was no difference in the frequency of peri-procedural complications. There were similar improvements in NYHA functional class and similar reduction in QRS duration, but more patients reported unchanged global assessment status in the upgraded group. Total and cause-specific mortality at 1 year was low and the same in both groups. Conclusions More than one quarter of all CRT procedures are upgrades from existing systems, although this group has not been subject to randomized clinical trials. Our data suggest that there are no significant differences in clinical outcomes or complication rates between upgrades and de novo procedures. Clinical study no NCT 01185392 [ABSTRACT FROM AUTHOR]