TY - JOUR
T1 - Electrophysiological characteristics of septal hypertrophy in patients with hypertrophic obstructive cardiomyopathy and moderate to severe symptoms
AU - Schumacher, Burghard
AU - Gietzen, Frank H.
AU - Neuser, Hans
AU - Schümmelfeder, Joachim
AU - Schneider, Michael
AU - Kerber, Sebastian
AU - Schimpf, Rainer
AU - Wolpert, Christian
AU - Borggrefe, Martin
PY - 2005/10/4
Y1 - 2005/10/4
N2 - Background - In hypertrophic obstructive cardiomyopathy, regional hypertrophy, myocardial replacement scarring, expanded interstitial fibrosis, and myocardial disarray can be found. The electrophysiological consequences of this substrate have not yet been investigated. Thus, the aim of this study was to assess the local electrophysiological characteristics of regional left ventricular (LV) septal hypertrophy. Methods and Results - In 9 patients with hypertrophic obstructive cardiomyopathy, electroanatomic voltage mapping of the LV was performed during sinus rhythm to determine the regional voltage amplitude. In addition, the morphology of the regional bipolar endocardial electrogram was assessed. During multisite LV stimulation, the stimulus-to-V intervals in both septal hypertrophy and the lateral LV myocardium were determined. Bipolar electroanatomic voltage mapping revealed a significant reduction in regional voltage amplitude in septal hypertrophic areas compared with lateral LV areas without evidence of hypertrophy (0.41±0.24 versus 13.5±1.85 mV; P<0,001). Local bipolar electrogram analysis demonstrated fractionated and prolonged endocardial potentials in septal hypertrophic areas (with split potentials present in 6 patients) that were not revealed at lateral myocardial sites (110.1±24.6 versus 80.1±6.6 ms; P=0.005). The stimulus-to-V interval was significantly longer (62.9±10.3 versus 24.1±9.1 ms; P=0.005) in septal hypertrophic areas compared with the lateral LV. Conclusions - In LV regions with extensive hypertrophy, a marked reduction of bipolar voltage amplitude can be found, as well as local conduction delay and conduction block. This result is consistent with the findings of regional myocardial scarring and may contribute to the increased incidence of ventricular tachyarrhythmias in patients with hypertrophic obstructive cardiomyopathy.
AB - Background - In hypertrophic obstructive cardiomyopathy, regional hypertrophy, myocardial replacement scarring, expanded interstitial fibrosis, and myocardial disarray can be found. The electrophysiological consequences of this substrate have not yet been investigated. Thus, the aim of this study was to assess the local electrophysiological characteristics of regional left ventricular (LV) septal hypertrophy. Methods and Results - In 9 patients with hypertrophic obstructive cardiomyopathy, electroanatomic voltage mapping of the LV was performed during sinus rhythm to determine the regional voltage amplitude. In addition, the morphology of the regional bipolar endocardial electrogram was assessed. During multisite LV stimulation, the stimulus-to-V intervals in both septal hypertrophy and the lateral LV myocardium were determined. Bipolar electroanatomic voltage mapping revealed a significant reduction in regional voltage amplitude in septal hypertrophic areas compared with lateral LV areas without evidence of hypertrophy (0.41±0.24 versus 13.5±1.85 mV; P<0,001). Local bipolar electrogram analysis demonstrated fractionated and prolonged endocardial potentials in septal hypertrophic areas (with split potentials present in 6 patients) that were not revealed at lateral myocardial sites (110.1±24.6 versus 80.1±6.6 ms; P=0.005). The stimulus-to-V interval was significantly longer (62.9±10.3 versus 24.1±9.1 ms; P=0.005) in septal hypertrophic areas compared with the lateral LV. Conclusions - In LV regions with extensive hypertrophy, a marked reduction of bipolar voltage amplitude can be found, as well as local conduction delay and conduction block. This result is consistent with the findings of regional myocardial scarring and may contribute to the increased incidence of ventricular tachyarrhythmias in patients with hypertrophic obstructive cardiomyopathy.
KW - Arrhythmia
KW - Cardiomyopathy
KW - Electrophysiology
KW - Hypertrophy
UR - http://www.scopus.com/inward/record.url?scp=26944448894&partnerID=8YFLogxK
U2 - 10.1161/CIRCULATIONAHA.104.515643
DO - 10.1161/CIRCULATIONAHA.104.515643
M3 - Article
C2 - 16186424
AN - SCOPUS:26944448894
SN - 0009-7322
VL - 112
SP - 2096
EP - 2101
JO - Circulation
JF - Circulation
IS - 14
ER -