Left ventricular function, cardiac dysrhythmias, atrial activation, and volumes in nondipper hypertensive individuals with left ventricular hypertrophy

Background Arrhythmic patterns and left ventricular geometric adaptations t o pressure overload were investigated in 76 patients with untreated borderl ine-to-moderate sustained essential hypertension studied by 2-dimensional a nd M-mode echocardiography, 12-lead, Halter, and signal-averaged electrocar diography, and ambulatory blood pressure monitoring. Methods and Results Sixty-two age- and sex-matched normal adults were chose n for data comparison. Hypertrophic hypertensive patients were subdivided i nto 2 subgroups: 44 patients with nocturnal blood pressure reduction (dippe rs) and 32 patients without it (nondippers). Common afterload and diastolic function indexes were found to be lower in combined nondipper and dipper g roups, but only fractional shortening decreased in nondippers. The number o f premature atrial and ventricular contractions per hour was high in dipper s and nondippers, with no statistically significant differences between the m; atrial and ventricular complex dysrhythmias were similar. Signal-average d electrocardiography showed a prolonged P-wave duration in dipper and nond ipper patients with high atrial volumes but no late ventricular potentials and no difference in quantitative P-wave analysis. left atrial volumes, P-w ave duration, and premature atrial contractions were found to be positively linked to left ventricular hypertrophy. In nondipper patients a linear cor relation was observed between left atrial volume and P-wave duration, altho ugh supraventricular ectopic activity was connected to left atrial volume e nlargement both in dipper and nondipper patients. Conclusions These data suggest that the nondipper pattern is not linked to a worse arrhythmogenic substrate; only atrial volume increase may be relate d to significant supraventricular activity and prolonged atrial activation in nondipper patients, but late ventricular potentials are uncommon in hype rtrophic hypertensive patients.