Effect of transcoronary ablation of septal hypertrophy on clinical outcome in hypertrophic obstructive cardiomyopathy associated with atrial fibrillation.

BACKGROUND: Relatively few reports on the clinical impact of atrial fibrillation (AF) in hypertrophic obstructive cardiomyopathy (HOCM) are available. The aims of our study are to report the effect of transcoronary ablation of septal hypertrophy (TASH) on clinical outcome in HOCM associated with AF and to evaluate the influence of AF on symptoms and quality of life in HOCM. PATIENT AND METHODS: In 80 consecutive patients (38 f, mean age 56 +/- 17 years) with severely symptomatic HOCM referred for interventional treatment, we analyzed the prevalence of AF based on 240 Holter ECG recordings and patients' history, retrospectively. Symptoms, quality of life, number of hospital admissions and hemodynamic performance were obtained in all patients before and after TASH. Mortality was additionally investigated by letter and telephone contact. RESULTS: The overall prevalence of AF was 29%. Paroxysmal AF was detected in 17 pts (21.3%), persistent AF in 5 pts (6.3%). Only 1 pt (1.3%) suffered from permanent AF. Symptoms due to AF were present in 52.6% of the AF patients. Quality of life score was markedly improved after TASH (15.9 +/- 3.8 vs. 20.7 +/- 3.8, p < 0.001) with no difference between sinus rhythm and atrial fibrillation. However, hospital admissions were more frequent in the AF group (0.85 +/- 1.84 vs. 0.28 +/- 0.81, p = 0.03) in 32 +/- 13 months. AF patients suffered more often from syncope before TASH (30 +/- 70% vs. 10 +/- 30%, p = 0.008). Two patients with sinus rhythm at baseline died after 32 +/- 13 months from cardiovascular cause. CONCLUSIONS: Atrial fibrillation is the major cardiac arrhythmia in severe HOCM. The majority of AF patients demonstrate AF specific symptoms. The paroxysmal type of atrial fibrillation dominates by far. Both patients with and without atrial fibrillation showed similar quality of life with marked improvement after TASH.

Long and short QT syndrome.

In the past decade molecular genetic analysis has greatly expanded our knowledge about inherited arrhythmogenic syndromes. The congenital long QT syndrome (LQTS) and the recently described short QT syndrome (SQTS), with the defining characteristic of abnormal prolongation or shortening of the QTc interval on the surface electrocardiogram, are caused by cardiac ion channel dysfunctions. These "channelopathies" show a high degree of genetic heterogeneity of the molecular pathways in terms of the relationships between genetic defects and phenotypic expression. In this brief review we summarize the current understanding of the molecular basis of long and short QT syndrome with focus on the impact of molecular genetics on the clinical management of these diseases.

Endocardial radiofrequency ablation of septal hypertrophy. A new catheter-based modality of gradient reduction in hypertrophic obstructive cardiomyopathy.

Transcoronary alcohol ablation of septal hypertrophy (TASH) is a therapeutic catheter based option and an alternative to surgery in the treatment of patients with hypertrophic obstructive cardiomyopathy. However, the anatomic variability of the vascularisation of the obstructing septal bulge may limit the therapeutic efficacy. Thus, we examined an endocardial approach as an alternative. Based on the effects of radiofrequency energy in the treatment of cardiac arrhythmias this is the first report about the use of this modality. It refers to a 45-year-old patient with severe HOCM. The energy was applied by using a cooled-tip ablation catheter at the right side of the ventricular septum. The site corresponded to the obstructing area of the left ventricle. The following changes could be observed: a reduction of the intraventricular pressure gradient during the therapeutic session, a gradient reduction at cycle exercise as assessed by Doppler echocardiography 7 days after intervention, a subaortic septal hypokinesia, an enlargement of the left ventricular outflow tract, a reduction of the septal thickness and an increase in the exercise capacity using the 6-minute walk test. These changes are in accordance with the results after TASH and surgical treatment. The new modality might extend the possibilities in the catheter-based treatment of patients with severe HOCM.