This e-book starts with a comprehensive overview of the basic principles in Electrocardiography (ECG) with just enough depth to lift the reader above the crowd when it comes to understanding the ...physics behind ECG. Subsequent chapters provide an approach to the analysis of the ECG followed by sections with insight into conduction abnormalities, arrhythmia, and myocardial ischemia.
Randomized controlled trials have shown superior survival rates with implantable cardioverter defibrillators (ICDs) compared with antiarrhythmic drugs in survivors of cardiac arrest and ...life-threatening ventricular tachyarrhythmias, as well as in high-risk patients with ischemic heart disease and inducible ventricular tachycardia (VT). Current defibrillators are small and implanted with techniques similar to standard pacemakers. They provide high-energy shocks for ventricular fibrillation (VF) and rapid VT, antitachycardia pacing for monomorphic VT, and antibradycardia pacing. Limited evidence suggests that ICD therapy is cost-effective when compared with other widely accepted treatments. The use of ICDs is likely to continue to expand in the future. Ongoing clinical trials will define further prophylactic indications of the ICD and clarify its cost-effectiveness ratio in different clinical settings.
Calmodulin (CaM) mutations are associated with cardiac arrhythmia susceptibility including the congenital long QT syndrome (LQTS). We identified two novel CaM mutations in children with LQTS ...associated with cardiac arrest, and performed studies to elucidate the functional consequences of each molecular defect. The first mutation was discovered in a male infant with a ventricular septal defect and fetal bradycardia born to healthy parents. His ECG on postnatal day 1 revealed bradycardia and very prolonged QTc (651 msec). At age 2-days, he developed 2:1 AV block, profound bradycardia (50 bpm) and cardiogenic shock. He was resuscitated and received a pacemaker. Targeted DNA sequencing revealed a de novo mutation in CALM2 (D132H). A second novel mutation was discovered in a three year-old boy who suffered witnessed cardiac arrest. His initial rhythm was ventricular fibrillation, and after successful defibrillation an ECG recording revealed a QTc of 574 msec. The parents were healthy with normal QTc intervals. Exome sequencing of the parent-child trio demonstrated a de novo mutation in CALM1 (D132V). Both novel mutations affect the same conserved aspartate residue within the C-domain EF-hand-IV Ca2+ binding motif. Further studies elucidated biochemical and functional effects of the mutations. Measurements of Ca2+ binding affinity of CaM-D132H indicated extremely weak binding to the C-domain (Kd > 150 μM) with significant structural perturbations. Voltage-clamp recordings of human induced pluripotent stem cell (iPSC) derived cardiomyocytes transiently expressing wildtype or mutant CaM demonstrated that both mutations caused impaired Ca2+-dependent inactivation (CDI) of voltage-gated Ca2+ current. Neither mutant affected voltage-dependent inactivation of Ba2+ currents. Our findings implicate impaired CDI in human cardiomyocytes as the plausible mechanism for LQTS associated with CaM mutations.
a Department of Cardiovascular Surgery, University Hospital, rue du Bugnon 46, Lausanne, Switzerland
b Department of Cardiology, University Hospital, Lausanne, Switzerland
* Corresponding author. ...Tel.: +41-21-314-2280; fax: +41-21-314-2278 patrick.ruchat{at}chuv.hospvd.ch
The CoxMaze-III procedure still remains the gold standard in surgical treatment of atrial fibrillation.The major hazard of atrial fibrillation is thromboembolic event to the brain. Left atrial appendage (LAA) represents the source of thrombus and subsequent embolism although LAA obliteration is a key point to prevent thrombogenesis. We describe a simplified off-pump compartmentalization procedure using epicardial radiofrequency ablation of the left atrium and LAA stapling on the beating heart without cardiopulmonary bypass.
Key Words: Atrial fibrillation; Beating heart surgery; Radiofrequency ablation; Arrhythmia surgery; Stapling technique
Abstract Purpose The goal of the study was to assess the causes and analyze the cases of sudden cardiac death (SCD) victims referred to the department of forensic medicine in Lausanne, with a ...particular focus on sports-related fatalities including also leisure sporting activities. To date, no such published assessment has been done nor for Switzerland nor for the central Europe. Methods This is a retrospective study based on autopsy records of SCD victims, from 10 to 50 years of age, performed at the University Centre of Legal Medicine in Lausanne from 1995 to 2010. The study population was divided into two groups: sport-related (SR) and not sport-related (NSR) SCDs. Results During the study period, 188 cases of SCD were recorded: 166 (88%) were NSR and 22 (12%) SR. The mean age of the 188 victims was 37.3 ± 10.1 years, with the majority of the cases being male (79%). A cause of death was established in 84%, and the pathology responsible for death varied according to the age of the victims. In the NSR group, the mean age was 38.2 ± 9.2 years and there was 82% of male. Coronary artery disease (CAD) was the main diagnosis in the victims aged 30–50 years. The majority of morphologically normal hearts were observed in the 15–29 year age range. There was no case in the 10–14 year age range. In the SR group, 91% of victims died during leisure sporting activities. In this group the mean age was 30.5 ± 13.5 years, with the majority being male (82%). The main cause of death was CAD, with 6 cases (27%) and a mean age of 40.8 ± 5.5 years. The youngest victim with CAD was 33 years old. A morphologically normal heart was observed in 5 cases (23%), with a mean age of 24.4 ± 14.9 years. The most frequently implicated sporting activities were hiking (26%) and swimming (17%). Conclusion In this study, CAD was the most common cause of death in both groups. Although this pathology most often affects adults over 35 years of age, there were also some victims under 35 years of age in both groups. SCDs during sport are mostly related to leisure sporting activities, for which preventive measures are not yet usually established. This study highlights also the need to inform both athletes and non athletes of the cardiovascular risks during sport activities and the role of a forensic autopsy and registries involving forensic pathologists for SR SCD.
Patients with well-tolerated sustained monomorphic ventricular tachycardia (SMVT) and left ventricular ejection fraction (LVEF) over 30% may benefit from a primary strategy of VT ablation without ...immediate need for a 'back-up' implantable cardioverter-defibrillator (ICD).
One hundred and sixty-six patients with structural heart disease (SHD), LVEF over 30%, and well-tolerated SMVT (no syncope) underwent primary radiofrequency ablation without ICD implantation at eight European centres. There were 139 men (84%) with mean age 62 ± 15 years and mean LVEF of 50 ± 10%. Fifty-five percent had ischaemic heart disease, 19% non-ischaemic cardiomyopathy, and 12% arrhythmogenic right ventricular cardiomyopathy. Three hundred seventy-eight similar patients were implanted with an ICD during the same period and serve as a control group. All-cause mortality was 12% (20 patients) over a mean follow-up of 32 ± 27 months. Eight patients (40%) died from non-cardiovascular causes, 8 (40%) died from non-arrhythmic cardiovascular causes, and 4 (20%) died suddenly (SD) (2.4% of the population). All-cause mortality in the control group was 12%. Twenty-seven patients (16%) had a non-fatal recurrence at a median time of 5 months, while 20 patients (12%) required an ICD, of whom 4 died (20%).
Patients with well-tolerated SMVT, SHD, and LVEF > 30% undergoing primary VT ablation without a back-up ICD had a very low rate of arrhythmic death and recurrences were generally non-fatal. These data would support a randomized clinical trial comparing this approach with others incorporating implantation of an ICD as a primary strategy.
Objective. To assess the impact of introducing clinical practice guidelines on acute coronary syndrome without persistent ST segment elevation (ACS) on patient initial assessment. Design. Prospective ...before–after evaluation over a 3-month period. Setting. The emergency ward of a tertiary teaching hospital. Patients. All consecutive patients with ACS evaluated in the emergency ward over the two 3-month periods. Intervention. Implementation of the practice guidelines, and the addition of a cardiology consultant to the emergency team. Main outcome measures. Diagnosis, electrocardiogram interpretation, and risk stratification after the initial evaluation. Results. The clinical characteristics of the 328 and 364 patients evaluated in the emergency ward for suspicion of ACS before and after guideline implementation were similar. Significantly more patients were classified as suffering from atypical chest pain (39.6% versus 47.0%; P = 0.006) after guideline implementation. Guidelines availability was associated with significantly more formal diagnoses (79.9% versus 92.9%; P < 0.0001) and risk stratification (53.7% versus 65.4%, P < 0.0001) at the end of initial assessment. Conclusion. Guidelines implementation, along with availability of a cardiology consultant in the emergency room had a positive impact on initial assessment of patients evaluated for suspicion of ACS. It led to increased confidence in diagnosis and stratification by risk, which are the first steps in initiating effective treatment for this common condition.
Aims
Estimates of the left ventricular ejection fraction (LVEF) in patients with life-threatening ventricular arrhythmias related to coronary artery disease (CAD) have rarely been reported despite it ...has become the basis for determining patient's eligibility for prophylactic defibrillator. We aimed to determine the extent and distribution of reduced LVEF in patients with sustained ventricular tachycardia or ventricular fibrillation.
Methods and results
252 patients admitted for ventricular arrhythmia related to CAD were included: 149 had acute myocardial infarction (MI) (Group I, 59%), 54 had significant chronic obstructive CAD suggestive of an ischaemic arrhythmic trigger (Group II, 21%) and 49 patients had an old MI without residual ischaemia (Group III, 19%). 34% of the patients with scar-related arrhythmias had an LVEF ≥40%. Based on pre-event LVEF evaluation, it can be estimated that less than one quarter of the whole study population had a known chronic MI with severely reduced LVEF. In Group III, the proportion of inferior MI was significantly higher than anterior MI (81 vs. 19%; absolute difference, −62; 95% confidence interval, −45 to −79; P ≤ 0.0001), though median LVEF was higher in inferior MI (0.37 ± 10 vs. 0.29 ± 10; P = 0.0499).
Conclusion
Patients included in defibrillator trials represent only a minority of the patients at risk of sudden cardiac death. By applying the current risk stratification strategy based on LVEF, more than one third of the patients with old MI would not have qualified for a prophylactic defibrillator. Our study also suggests that inferior scars may be more prone to ventricular arrhythmia compared to anterior scars.
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