Howard Marshall

Atrioventricular nodal ablation and implantation of mode switching dual chamber pacemakers: effective treatment for drug refractory paroxysmal atrial fibrillation

Objective To assess the effect of atrioventricular node ablation and implantation of a dual chamber, mode switching pacemaker on quality of life, exercise capacity, and left ventricular systolic function in patients with drug refractory paroxysmal atrial fibrillation. Patients 18 consecutive patients with drug refractory paroxysmal atrial fibrillation. Methods Quality of life was assessed before and after the procedure using the psychological general wellbeing index (PGWB), the McMaster health index (MHI), and a visual analogue scale for cardiac symptoms. Nine of the patients also underwent symptom limited exercise tests and echocardiography to assess left ventricular systolic function. Results The procedure allowed a reduction in antiarrhythmic drug treatment (pu2009<u20090.01). PGWB and symptom scores improved (pu2009<u20090.01) but the MHI score did not change. Left ventricular systolic function and exercise capacity were unchanged. Conclusions Atrioventricular node ablation and implantation of a DDDR/MS pacemaker is effective treatment for refractory paroxysmal atrial fibrillation, producing improved quality of life while allowing a reduction in drug burden. The popularity of the treatment is justified, but further studies are needed to determine optimum timing of intervention.

Noninvasive Assessment of Atrial Substrate Change after Wide Area Circumferential Ablation: A Comparison with Segmental Pulmonary Vein Isolation

Background: The wide area circumferential ablation (WACA) approach to atrial fibrillation is thought to result in ‘substrate modification’ perhaps related to autonomic denervation. We examined this prospectively by comparing WACA and segmental pulmonary vein isolation (PVI) using noninvasive surrogate markers.

Haemodynamic effects of cardiac resynchronization therapy using single-vein, three-pole, multipoint left ventricular pacing in patients with ischaemic cardiomyopathy and a left ventricular free wall scar: the MAESTRO study

AIMSnThe clinical response to cardiac resynchronization therapy (CRT) is variable. Multipoint left ventricular (LV) pacing could achieve more effective haemodynamic response than single-point LV pacing. Deployment of an LV lead over myocardial scar is associated with a poor haemodynamic response to and clinical outcome of CRT. We sought to determine whether the acute haemodynamic response to CRT using three-pole LV multipoint pacing (CRT3P-MPP) is superior to that to conventional CRT using single-site LV pacing (CRTSP) in patients with ischaemic cardiomyopathy and an LV free wall scar.nnnMETHODS AND RESULTSnSixteen patients with ischaemic cardiomyopathy [aged 72.6 ± 7.7 years (mean ± SD), 81.3% male, QRS: 146.0 ± 14.2 ms, LBBB in 14 (87.5%)] in whom the LV lead was intentionally deployed straddling an LV free wall scar (assessed using cardiac magnetic resonance), underwent assessment of LV + dP/dtmax during CRT3P-MPP and CRTSP. Interindividually, the ΔLV + dP/dtmax in relation to AAI pacing with CRT3P-MPP (6.2 ± 13.3%) was higher than with basal and mid CRTSP (both P < 0.001), but similar to apical CRTSP. Intraindividually, significant differences in the ΔLV + dP/dtmax to optimal and worst pacing configurations were observed in 10 (62.5%) patients. Of the 8 patients who responded to at least one configuration, CRT3P-MPP was optimal in 5 (62.5%) and apical CRTSP was optimal in 3 (37.5%) (P = 0.0047).nnnCONCLUSIONSnIn terms of acute haemodynamic response, CRT3P-MPP was comparable an apical CRTSP and superior to basal and distal CRTSP. In the absence of within-device haemodynamic optimization, CRT3P-MPP may offer a haemodynamic advantage over a fixed CRTSP configuration.

Outcomes of Cardiac Resynchronization Therapy With or Without Defibrillation in Patients With Nonischemic Cardiomyopathy

BACKGROUNDnRecent studies have cast doubt on the benefit of cardiac resynchronization therapy (CRT) with defibrillation (CRT-D) versus pacing (CRT-P) for patients with nonischemic cardiomyopathy (NICM). Left ventricular myocardial scar portends poor clinical outcomes.nnnOBJECTIVESnThe aim of this study was to determine whether CRT-D is superior to CRT-P in patients with NICM either with (+) or without (-) left ventricular midwall fibrosis (MWF), detected by cardiac magnetic resonance.nnnMETHODSnClinical events were quantified in patients with NICM who werexa0+MWF (nxa0=xa068) orxa0-MWF (nxa0=xa0184) who underwent cardiac magnetic resonance prior to CRT device implantation.nnnRESULTSnIn the total study population,xa0+MWF emerged as an independent predictor of total mortality (adjusted hazard ratio [aHR]: 2.31; 95% confidence interval [CI]: 1.45 to 3.68), total mortality or heart failure hospitalization (aHR: 2.02; 95% CI: 1.32 to 3.09), total mortality or hospitalization for major adverse cardiac events (aHR: 2.02; 95% CI: 1.32 to 3.07), death from pump failure (aHR: 1.95; 95% CI: 1.11 to 3.41), and sudden cardiac death (aHR: 3.75; 95% CI: 1.26 to 11.2) over a maximum follow-up period of 14 years (median 3.8 years [interquartile range: 2.0 to 6.1 years] forxa0+MWF and 4.6 years [interquartile range: 2.4 to 8.3 years] forxa0-MWF). In separate analyses ofxa0+MWF andxa0-MWF, total mortality (aHR: 0.23; 95% CI: 0.07 to 0.75), total mortality or heart failure hospitalization (aHR: 0.32; 95% CI: 0.12 to 0.82), and total mortality or hospitalization for major adverse cardiac events (aHR: 0.30; 95% CI: 0.12 to 0.78) were lower after CRT-D than after CRT-P inxa0+MWF but not inxa0-MWF.nnnCONCLUSIONSnIn patients with NICM, CRT-D was superior to CRT-P inxa0+MWF but notxa0-MWF. These findings havexa0implications for the choice of device therapy in patients with NICM.

Cardiac Resynchronization Therapy Using Quadripolar Versus Non‐Quadripolar Left Ventricular Leads Programmed to Biventricular Pacing With Single‐Site Left Ventricular Pacing: Impact on Survival and Heart Failure Hospitalization

Background In cardiac resynchronization therapy (CRT), quadripolar (QUAD) left ventricular (LV) leads are less prone to postoperative complications than non‐QUAD leads. Some studies have suggested better clinical outcomes. Methods and Results Clinical events were assessed in 847 patients after CRT‐pacing or CRT‐defibrillation using either QUAD (n=287) or non‐QUAD (n=560), programmed to single‐site site LV pacing. Over a follow‐up period of 3.2 years (median [interquartile range, 1.90–5.0]), QUAD was associated with a lower total mortality (adjusted hazard ratio [aHR]: 0.32, 95% confidence interval [CI], 0.20–0.52), cardiac mortality (aHR: 0.36, 95% CI, 0.20–0.65), and heart failure (HF) hospitalization (aHR: 0.62, 95% CI, 0.39–0.99), after adjustment for age, sex, New York Heart Association class, HF etiology, device type (CRT‐pacing or CRT‐defibrillation), comorbidities, atrial rhythm, medication, left ventricular ejection fraction, and creatinine. Death from pump failure was lower with QUAD (aHR: 0.33; 95% CI, 0.18–0.62), but no group differences emerged with respect to sudden cardiac death. There were no differences in implant‐related complications. Re‐interventions for LV displacement or phrenic nerve stimulation, which were lower with QUAD, predicted total mortality (aHR: 1.68, 95% CI, 1.11–2.54), cardiac mortality (aHR: 2.61, 95% CI, 1.66–4.11) and HF hospitalization (aHR: 2.09, 95% CI, 1.22–3.58). Conclusions CRT using QUAD, programmed to biventricular pacing with single‐site LV pacing, is associated with a lower total mortality, cardiac mortality, and HF hospitalization. These trends were observed for both CRT‐defibrillation and CRT‐pacing, after adjustment for HF cause and other confounders. Re‐intervention for LV lead displacement or phrenic nerve stimulation was associated with worse outcomes.

AAI pacing for sick sinus syndrome: first choice on all counts

The British Pacing and Electrophysiology Group guidelines for pacemaker prescription recommend single chamber atrial pacing as the most appropriate pacing mode for sinus node disease in the absence of atrioventricular conduction disturbance.1 As such it offers a rare combination of maximum clinical effectiveness for the minimum cost and a good training opportunity. However, it seems that this message has yet to be translated into pacing practice in the UK.nnIn this issue of Heart , Clarke et al retrospectively analyses the pacing activity for sinus node disease in a tertiary pacing centre over five years.2 They conclude that in their centre £103u2009000 per year could have been saved by more judicious use of AAI pacing, largely by reducing the DDD implant rate. It seems likely that these potential savings are equally applicable to the rest of the UK. Current pacemaker prescribing for sinus node disease is frequently illogical, ignores current evidence, and misses out on training opportunities for junior staff.nnThe evidence to support atrial based pacing for sinus node disease, rather than single chamber ventricular pacing, is very strong. Numerous retrospective studies have demonstrated that mortality and morbidity are greater in ventricular only paced patients,3-5 and that the progression to chronic atrial fibrillation (AF) is less common in patients with atrial based pacing.3-10 Although these data may be criticised for the potential biases inherent in retrospective studies, since 1994 data have been available from the first prospective randomised study.11 Andersen et al were able to demonstrate a reduction in the frequency of AF and incidence of thromboembolism (5% v 18%) with atrial pacing after three years of follow up. The most recent analysis of this study (at 5.5 years of follow up) has also shown a significant reduction in all cause mortality (35.5% v …

Long-term requirement for pacemaker implantation after cardiac valve replacement surgery

BACKGROUNDnThe risk of permanent pacemaker implantation (PPI) after cardiac valve replacement surgery is thought to be highest in the postoperative period. Long-term risks are uncertain.nnnOBJECTIVEnThe purpose of this study was to determine rates and timing of PPI after cardiac valve replacement surgery.nnnMETHODSnWe compared PPI rates of patients undergoing aortic valve replacement (AVR; n = 111,674), mitral valve replacement (MVR; n = 18,402), AVR + MVR (n = 5166), AVR + MVR + tricuspid valve replacement (TVR; n = 114), or coronary artery bypass surgery (CABG) without valve replacement (n = 249,742).nnnRESULTSnOver a period of 14 years (median 3.9 years; interquartile range 1.1-7.4 years), cumulative PPI rates were 3.07-7.6 times higher (P < .001 for all) than after CABG, depending on the number of valves replaced. PPI risks after AVR were higher that those after MVR (hazard ratio [HR] 1.22; 95% confidence interval [CI] 1.16-1.28), AVR + MVR (HR 1.52; 95% CI 1.40-1.65), and AVR + MVR + TVR (HR 2.22; 95% CI 1.40-3.53), independent of known confounders. Cumulative PPI hazard rates from the postoperative period to 10 years after surgery increased after AVR (4.22%-14.4%), MVR (4.38%-15.6%), AVR + MVR (5.59%-18.3%), and AVR + MVR + TVR (7.89%-25.9%) (P < .001 for all). Age, male sex, emergency admission, and preexisting diabetes mellitus, renal impairment, and heart failure were independent predictors of PPI (P < .001 for all).nnnCONCLUSIONnValve replacement surgery was associated with a long-term risk of PPI. This was particularly high after dual and triple valve replacements. Age, male sex, emergency admission, and preexisting diabetes mellitus, heart failure, and renal impairment were independent predictors of PPI.

Late perforation of a defibrillator lead managed by percutaneous, intravenous extraction

We report the case of a patient with ischaemic cardiomyopathy who underwent cardiac resynchronization therapy with defibrillator back-up. He re-presented 3 weeks later with chest pain, having received two shocks. We describe a case of late perforation with the Riata lead causing inappropriate shocks.

Malposition of pacing lead into the left ventricle: a rare complication of pacemaker insertion

A 79-year-old woman presented with infection and erosion of a permanent pacemaker, which had been inserted 15u2005years earlier. A chest X-rays showed an abnormal position of ventricular lead, suggesting it was in the left rather than right ventricle (figure 1A, B). Transoesophageal echocardiography showed that it was positioned in the left ventricle due to passage through a patent foramen ovale (figure 1C). The active fix lead was inserted …

Local activation time derived from stored EGM is associated with failure of antitachycardia pacing in patients with implantable defibrillator.

Background :u2002Antitachycardia pacing (ATP) is an effective treatment of ventricular tachycardia (VT). However, persistent failure of ATP in some patients is well recognized.