Alcohol-induced right bundle branch block is associated with a benign outcome in HOCM after alcohol septum ablation (ASA).

INTRODUCTION: Alcohol septum ablation (ASA) is a treatment option for hypertrophic obstructive cardiomyopathy (HOCM). We examined the impact of ASA-induced bundle branch block (BBB) on clinical and hemodynamic features. METHODS AND RESULTS: We retrospectively analysed 98 HOCM patients with regard to ASA-induced BBB. Clinical examination was performed at baseline, early after ASA and at chronic follow-up (FU). ASA reduced left ventricular outflow tract gradient (LVOTG) during chronic FU (69.2 ± 41.6 pre vs. 31.8 ± 30.3 mmHg post ASA; p < 0.05) and interventricular septal diameter (21.7 ± 3.4 pre vs. 18.7 ± 5.0 mm post ASA; p < 0.05). ASA-induced early right BBB (RBBB) until discharge was observed in 44.9% and chronic RBBB at FU in 32.7%. Left BBB (LBBB) occurred in 13.3% early after ASA and in only 4.1% at chronic FU. Chronic RBBB was associated with more pronounced exercise-induced LVOTG reduction (102.1 ± 55.2 with vs. 73.6 ± 60.0 mmHg without; p < 0.05). 6-min-walk-test (6-MWT) and NYHA class were not affected by RBBB. LBBB had no influence on LVOTG, 6-MWT and symptoms. More ethanol was injected in patients with early RBBB (1.1 ± 0.4 vs. 0.8 ± 0.3 ml without; p < 0.05), who also showed higher mean CK release (827 ± 341 vs. 583 ± 279 U/l without; p < 0.05). Pacemaker implantation during FU was necessary in 11.5% of patients with early RBBB, 3.1% with chronic RBBB, 7.7% with early LBBB and 0% with chronic LBBB (p = n.s. for BBB vs. no BBB). CONCLUSION: ASA-induced RBBB is associated with a higher volume of infused ethanol and higher maximum CK release. RBBB does not adversely affect the clinical outcome or need for pacemaker implantation but was associated with higher exercise-induced LVOTG reduction during chronic FU.

[Indication for myocardial biopsy in myocarditis and dilated cardiomyopathy]. / Indikation der Herzmuskelbiopsie bei Myokarditis und dilatativer Kardiomyopathie.

This review may serve as a basis for evaluating publications on the topic "myocardial biopsy for myocarditis and dilated cardiomyopathy" in the clinical practice. The literature is particularly analyzed to answer the question, whether an endomyocardial catheter biopsy is indicated in patients with these myocardial disorders in the clinical routine besides its unequivocal scientific value. The judgment of the biopsy samples has been based on the classically histological and for years on the additional immunohistochemical and molecular biological-virological examination. The analysis of the literature data shows that outside scientific studies there is no indication to perform myocardial biopsy, or in other words, this procedure is not suitable for diagnosis, therapy, detection of early stages or prognostic evaluation in the disease spectrum "myocarditis, inflammatory heart disease, dilated cardiomyopathy". Reasons are the subjectivity in the judgment and interpretation of bioptic findings resulting in considerable interobserver variability, a missing standardization in biopsy performance, methods of examination and diagnostic criteria, the bioptic sampling error, missing therapeutic and prognostic consequences and potentially severe complications in performing myocardial biopsies. So far, the specificity of inflammatory changes in patients with dilated cardiomyopathy has not been proven in controlled blinded studies. The bioptic changes could be understood also as an unspecific inflammatory process in front of increasing pathophysiological evidence for myocardial inflammation in any form of heart failure. In addition, regarding the specific etiology of dilated cardiomyopathy, primarily a genetic, noninfectious or autoimmunologic origin plays an increasing role. The favorable clinical course and the very good prognosis of the acute, clinically diagnosed or supposed viral myocarditis should also be taken into account for the evaluation of myocardial biopsy. It should also be considered that the proof of causality between acute myocarditis and dilated cardiomyopathy is still lacking. Regarding the diagnosis "inflammatory cardiomyopathy" and multiple inflammatory subsets among patients with dilated cardiomyopathy or unclear regional contraction disorder, there is no adequate clinical validation of different diagnostic methods, criteria and interpretations so far. It is missleading to replace the well-established clinical diagnosis myocarditis by the bioptic diagnosis "inflammatory cardiomyopathy". However, endomyocardial catheter biopsy is clearly indicated in rare patients with fulminant myocarditis, giant-cell myocarditis and myocardial storage disease. Its probably underestimated role in sarcoid heart disease still needs to be clarified by systematic studies.