Influence of the left ventricular types on QT intervals in hypertensive patients

Objective: To investigate the possible electrophysiological background of the greater excitability of concentric and eccentric left ventricular hypertrophy types in relation to the asymmetric type. Methods: 187 patients with essential hypertension, without ishaemic heart disease were divided into three groups with regard to left ventricule type: concentric (relative wall thickness >0.42, interventricular septum/left ventricular posterior wall ≤1.3), eccentric (left ventricular diameter in systoles >32, relative wall thickness 1.3), and three subgroups: mild (interventricular septum or left ventricular posterior wall 11-12 mm), moderate (interventricular septum or left ventricular posterior wall 13-14 mm) and severe left ventricular hypertrophy (interventricular septum or left ventricular posterior wall ≥15 mm). In all patients QT intervals, QT dispersion, left ventricular mass index and ventricular arrhythmias were measured. An upper normal limit for QT corrected interval: 450/460 ms for men/women; for QT dispersion: 70 ms. Results: The QT corrected interval and QT dispersion were increased in severe concentric and eccentric left ventricular hypertrophy (443 and 480 ms for QT corrected; 53 and 45 ms for QT dispersion, respectively), not significantly. QT dispersion in men with severe left ventricular hypertrophy was significantly enlarged (67.5 vs. 30 ms, p=0.047). QT interval was significantly longer in patients with complex ventricular arrhythmias (p=0.037). Conclusion: No significant association of QT intervals or QT dispersion with the degree/type of left ventricular hypertrophy was found. QT corrected interval and QT dispersion tend to increase proportionally to the left ventricular mass only in the concentric and eccentric type

The prevalence of supraventricular arrhythmias with regard to the type and degree of left ventricular hypertrophy in patients with hypertensive heart disease

OBJECTIVES: We investigated the correlation between the type and degree of left ventricular hypertrophy and the prevalence of supraventricular arrhythmias in patients with hypertensive heart disease. METHODS: The study included 179 patients (79 men, 100 women, aged 43–80 years, median 68 years) with left ventricular hypertrophy. Patients were classified into three groups (concentric, eccentric and asymmetric types of hypertrophy) and into three subgroups (mild, moderate and severe hypertrophy). After discontinuation of all medication for 48 h, blood pressure was measured, electrocardiography and echocardiography performed and the prevalence of supraventricular arrhythmias assessed using Holter monitoring and bicycle ergometry. Antihypertensive drugs and duration of previous treatment were taken into consideration. RESULTS: Atrial fibrillation or paroxysmal supraventricular tachycardia were found in 43% of patients. The analysis showed no significant correlation between the prevalence of atrial fibrillation and/or paroxysmal supraventricular tachycardia and the degree (P = 0.607) and type of left ventricular hypertrophy (P = 0.455). However, the frequency of supraventricular premature beats was higher in the concentric and eccentric types than in the asymmetric type (P = 0.048) and increased with the degree of hypertrophy (significantly in men with the concentric type, P = 0.015). CONCLUSION: Concentric and eccentric types of left ventricular hypertrophy have a greater impact on the frequency of atrial arrhythmias. In the concentric type the prevalence of supraventricular premature beats correlates with the degree of left ventricular hypertrophy. Patients with moderate and severe concentric and eccentric left ventricular hypertrophy should be always tested using Holter monitoring and bicycle ergometry and treated with the maximum tolerable doses of antihypertensives, particularly with angiotensin-converting enzyme inhibitors/angiotensin receptor blockers