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Summary Background Electrophysiological alterations in atrial fibrillation (AF) may be genetically based and may lead to changes in ventricular repolarization. Short QT syndrome is a rare channelopathy with abbreviated ventricular repolarization and a propensity for AF. Aims To determine if minor unrecognized forms of short QT syndrome can explain some cases of lone AF. Methods We prospectively compared QT intervals in 66 patients with idiopathic lone AF and 132 age- and sex-matched controls. QT intervals were measured during sinus rhythm in each of the 12 surface electrocardiogram leads and corrected using Bazett's formula (QTc). QT intervals were also corrected using other formulae. Uncorrected QT and heart rate regression lines were compared between AF patients and controls. Results AF patients presented with a slower resting heart rate (64 ± 10 beats per minute [bpm] vs 69 ± 9 bpm; P = 0.0006). QTc intervals were shorter in AF patients in 11/12 electrocardiogram leads (significant in 7/12, borderline in 2/12; mean QTc 381 ± 21 ms vs 388 ± 22 ms; P = 0.02). QTc intervals were also shorter in AF patients, significantly or not, using other correction formulae. For similar heart rates, uncorrected QT intervals were shorter in patients when heart rates were greater than 70 bpm and longer when heart rates were less than 60 bpm. AF patients displayed steeper QT/heart rate regression line slopes than controls ( P = 0.009). Conclusion Heart rate is significantly slower and the rate dependence of ventricular repolarization is significantly altered in patients with lone AF compared with controls. Further study is warranted to determine if AF induces subsequent ventricular repolarization changes or if these modifications are caused by an underlying primary electrical disease.

Summary Background A programme for quality assurance and prevention of infection risk during implantation of cardiac medical devices (pacemakers and defibrillators) was set up in our hospital. Aim We sought to assess surgical site infection rate and compliance with infection-control practices (principally antibiotic prophylaxis). Methods Surgical site infections associated with implanted medical devices were monitored in patients during a 6-month period and a 1-year follow-up. Professional practices concerning the use of prophylactic antibiotics in surgery were assessed. Results The surgical site infection rate was 2.3%. Overall compliance was 45% for the use of antibiotic prophylaxis. Conclusions Optimal compliance with antibiotic prophylaxis was not reached in the present series, which demonstrated a surgical site infection rate of 2.3%. More effort must be made to achieve full compliance with preventive measures in the implantation of medical devices.

IntroductionVery narrow QRS has been described whose prevalence and prognosis relevance in the normal population is unknown.Methods546 healthy men between 50 and 60 yo (group 1) and 373 similar patients with coronary artery disease (368 men, EF < 50% in 40%) (group 2) underwent signal averaged ECG allowing precise measurement of QRS duration. All cause mortality was determined after 17±3 years follow-up.ResultsMean QRS duration was 97±13ms for group 1 and 103±16ms for group 2. 85 group 1 subjects (16%) had QRS < 85ms and 23 (4%) had QRS>120ms. 44 group 2 patients (12%) had QRS < 85ms and 44 (12%) had QRS>120ms. QRS were larger in case of lower EF, lack of previous angioplasty and multivessel disease.All cause mortality in group 1 was 10,4% (57/546): 6/85 in case of QRS120ms (p=ns compared to normal QRS duration). HR for all-cause mortality in case of QRS < 85ms was 0,75 (95% CI 0.32-1.76, p = 0,52) and 0,86 (95% CI 0.21-3.53, p = 0,84) for QRS >120ms.All cause mortality in group 2 was 29% (109/373): 7/44 in case of QRS 120ms (p=0.002 when compared to normal QRS duration). Adjusted HR for all-cause mortality in case of QRS < 85ms was 0,65 (95% CI 0.29-1.45, p = 0,29) and 1.73 (95% CI 1.02-2.94, p = 0,05) for QRS > 120ms.All cause mortality in group 2 was 29% (109/373): 7/44 in case of QRS 120ms (p=0.002 when compared to normal QRS duration). Adjusted HR for all-cause mortality in case of QRS < 85ms was 0,65 (95% CI 0.29-1.45, p = 0,29) and 1.73 (95% CI 1.02-2.94, p = 0,05) for QRS > 120ms.Late potentials (LP) were present in SA-ECG in 116 group 1 subjects (21%). LP were present in 100 group 2 patients (27%) and were significantly related to multivessel disease, altered EF, lack of revascularization or of angioplasty. LP were more frequently observed in case of QRS > 120ms in both groups. LP were nor related to all-cause mortality in both groups.ConclusionQRS “narrower than normal” (< 85ms) can be observed in a significant porpotion of healthy males between 50 and 60 years old and in similar patients with ischemic heart disease. In opposition to QRS > 120 msec which are independantly related to a higher all-cause mortality in coronary artery disease patients, QRS

Introduction Both type 1 Myotonic Dystrophy (Steinert disease) and Brugada syndrome may be complicated by conduction disturbances and sudden death. ST elevation in the right precordial leads is the hallmark of Brugada syndrome but may be seen in some myopathies. Mutations in DMPK gene in Steinert pts may lead to cytosolic accumulation of muted toxic RNA or altered alternate splicing of some RNA potentially causing sodium channel dysfunctions. The prevalence of Brugada ECG pattern in Steinert disease is unknown. Methods we perform ajmaline challenge test (1 mg/kg over 5 min) during electrophysiological (EP) testing in a population of 44 Steinert disease pts (27 men, 41±15 years old) without ST elevation at baseline. Left ventricular EF was normal in each case. The presence of type 1 ST elevation (> 2 mm J elevation with coved ST and negative T wave) after ajmaline challenge was correlated to clinical, ECG and electrophysiological variables. Results 8 pts (18%) present type 1 ST elevation in the right precordial leads after ajmaline infusion. Brugada pattern was more often seen in men: 7/27 (26%) vs 1/17 (6%) (p=0.09). Patients with negative ajmaline test presented more often with fascicular block: 13/35 (27%) versus none (p=0.03). Brugada pattern was not correlated to age, symptoms, PR interval, QRS, QT or QTc durations, HV interval (at baseline or after ajmaline), presence of bundle branch block, of late potentials at SA-ECG or inducibility of ventricular arrhythmias at EP study. Nine pts were implanted with a pace maker and four with an ICD. Significant or symptomatic bradycardia did not happen in any non implanted pts, while only one pt presented with malignant ventricular arrhythmias during the 6.3±2.6 years follow-up (ventricular fibrillation with hypokaliemia in an ajmaline negative pt). Conclusion Brugada ECG pattern can be elicited by class 1 drug in 18% of Steinert disease pts and especially in men. Presence of type 1 ST elevation under class 1 drug in Steinert disease do not seem to have some significant clinical or ECG correlations.

Introduction The Epicor system ® is based on high intensity focused ultrasound (HIFU) energy used for creating a wide circumferential linear left atrial lesion encircling both left atrial posterior wall and pulmonary veins (box lesion) and provides long-term cure in patients with atrial fibrillation undergoing heart surgery. Whether if acute complete disconnection of the box lesion is achieved by application of HIFU is unknown. Methods bipolar pacing and detection into the box lesion was studied in 9 pts (5 men, 77 ± 18 yo) undergoing heart surgery (5 aortic valve replacement, 3 mitral valve repair or replacement and one coronary by-pass) using bipolar electrophysiological catheter and a real time telemetry (Medtronic CareLink ® programmer), just after completion of the ablation process on the beating heart prior to initiation of extracorporeal circulation. Sinus rhythm was present or obtained using internal cardioversion in each before the ablation process. Results Entrance block was absent in 7 (1 to 1 conduction from sinus rhythm inside the box lesion), undetermined in one and present in one (dissociated slow local rhythm). Exit block was lacking in 6 (capture of the cardiac rate by pacing inside the box lesion) and present in 3 (dissociated sinus rhythm from the paced area). Conclusion Acute complete block of the Epicor ® HIFU induced box lesion is lacking in the vast majority of pts despite completion of the energy deliverance according to the automated ablation process. Whether block later happens, or whether supplementary applications would increase the electrophysiological and clinical success rate is unknown.

Background Cardiac Resynchronization Therapy (CRT) improves morbidity and mortality in systolic heart failure. Elderly patients are under represented in large clinical trials although incidence of heart failure is high in this population. Method we considered 146 consecutive patients 75 years old with standard indication for CRT implanted between 2005 and 2007. Mean age was 79 yo, 72% males, EF = 27%, ischemic heart disease (IHD) 46%, Atrial Fibrillation 54%, CRT-D: 16%. Minimal follow-up was 12 months. Total mortality, clinical improvement (gain > 1 NYHA class without hospitalization for congestive heart failure) and combined criteria (mortality and clinical improvement) were retrospectively assessed. Results Mean follow-up is 25 +/-12 months. Data are complete for 137 patients (94.2%). Survival rate is 65%, clinical improvement is achieved in 51% and combined criteria in 45%. Independent factors of non response (p Causes of deaths are: terminal heart failure: 35 pts, sudden cardiac death: 1 pt, non cardiac death: 13 pts and unknown: 2 pts. Conclusion CRT is effective in elderly patients. Factors of non response are similar to those observed in younger population. CRT-P appears to be the most suitable device for this population. (Voir tableau ci-dessous) Multivariate analysis OR (IC 95%) Combined criteria Total Mortality Clinical improvement NYHA IV 4,1 (1.5–12.4) 3.1 (1.2–8.5) 2.5 (1–6.6) IHD 2,2 (1–4.8) 3.4 (1.5–7.9) NS CRT-D NS 3.2 (1.2–8.8) NS Atrial fibrillation 2,7 (1.3–5.8) 2.2 (1–5.1) NS No ACEI/ARB 2,7 (0.9–8.8) NS NS Renal failure (creatinine > 10μm/l) 1,1 (1–1.2) NS 1.2 (1.1–1.3) Doses of diuretics NS 1.03 (1–1.1) NS