Prognostic value of intraventricular dyssynchrony according to clinical stage of left ventricular impairment

Left ventricular systolic dyssynchrony in patients with Kawasaki disease: a real-time three-dimensional echocardiography study

The left ventricular (LV) systolic dyssynchrony index (SDI) is an important prognostic indicator for many cardiovascular diseases; however, the characteristics of the SDI in patients with Kawasaki disease (KD) are unknown. In this study, we aimed to identify and quantify the SDI using real-time three-dimensional echocardiography (RT3DE) in KD patients during different phases. In addition, we intended to explore whether the SDI is associated with systolic dysfunction. Seventy consecutive KD patients and seventy age- and sex-matched controls were enrolled. The SDIs (percent of cardiac cycle) of 16 segments (16-SDI%) and 12 segments (12-SDI%) were calculated based on the defined standard deviation of each segment time from end diastole to the minimal systolic volume according to the 17-segment model (apex excluded). In the acute phase, the 16-SDI% and 12-SDI% were significantly higher in KD patients than in controls (4.40 ± 0.14 vs. 1.98 ± 0.12, P = 0.000; 3.55 ± 1.21 vs. 1.67 ± 0.93, P = 0.009, respectively), and patients with coronary artery aneurysm (CAA) exhibited higher 16-SDI% (P = 0.021) and 12-SDI% (P = 0.034) than patients without CAA. In the convalescent phase, patients with CAA still had higher 16-SDI% (P = 0.002) and 12-SDI% (P = 0.031) than controls, while the SDI in patients without CAA recovered to normal. The 16-SDI% was negatively correlated with the LV ejection fraction obtained from RT3DE (r = - 0.845, P = 0.000). Mechanical dyssynchrony is prevalent in KD patients during the acute phase and transient in patients without CAA, while patients with CAA still have impaired synchrony even in the convalescent phase. LV systolic dysfunction is associated with increased dyssynchrony. RT3DE is a valuable modality for identifying and quantifying dyssynchrony in KD patients.

Left ventricular dyssynchrony in hypertensive patients without congestive heart failure

BACKGROUND

Normal left ventricular (LV) systolic function is present in as many as 50% of patients with congestive heart failure. The majority of such patients have systemic hypertension. Recent studies have demonstrated LV dyssynchrony among patients with heart failure and normal systolic function. However, it is unclear whether such abnormalities exist in hypertensive patients who have not developed clinical evidence of heart failure.

METHODS

Hospitalized patients with established hypertension undergoing echocardiography who met the following criteria were eligible for the study: LV ejection fraction (EF) >or= 50%, wall >or=11 mm, absence of valvular or known ischemic disease, and normal QRS duration. Complete 2-Dimensional and Doppler echocardiography studies with tissue Doppler imaging (TDI) were performed in all patients. Dyssynchrony was measured using time from QRS to peak systolic velocity on TDI (T-P) in 3 apical views. Normal values for dyssynchrony were established in a group of normotensive patients with normal echocardiography studies.

RESULTS

The study included 42 patients (19 women, 23 men with a, mean age of 59.6 y (range 32-96 y). Left ventricular dyssynchrony was common, occurring in 20 of 42 patients (47.6%). Dyssynchrony assessed with the maximum T-P (T-Pmax) was significantly related to LV mass (r = 0.32, p = 0.036), left atrial volume (r = 0.59, p < 0.0001), and LV sphericity index (0.32, p = 0.037). Dyssynchrony was not related to age or LV filling pressure calculated from the Doppler study.

CONCLUSIONS

Left ventricular dyssynchrony is common among hypertensive patients with normal LV systolic function and no evidence of congestive heart failure. The severity of LV dyssynchrony is related to the magnitude of LV hypertrophy, left atrial size, and LV remodeling.