Diurnal characteristics of heart rate variability in patients with sarcoidosis

BACKGROUND

The aim of this study was to evaluate autonomic nervous system function by measuring heart rate variability (HRV) in patients with sarcoidosis without known cardiac manifestations.

PATIENTS AND METHODS

The study comprised 61 participants, including 31 patients with sarcoidosis without known cardiac manifestations and 30 healthy volunteers. All participants underwent echocardiographic examination, 12-channel electrocardiography (ECG), and 24-h Holter monitoring. HRV parameters were determined and compared between the groups.

RESULTS

There were no differences between groups with regard to age, body mass index, systolic and diastolic blood pressure, or heart rate at the time of admission. In the time domain analyses, the 24-h, daytime, and night-time standard deviations of all normal-to-normal R‑R interval (SDNN) values were significantly lower in patients with sarcoidosis than those in the controls. The frequency domain analyses showed that 24-h and daytime low-frequency (LF) values, 24-h, daytime, and night-time high-frequency (HF) values were significantly lower in the patient group compared with the control group, whereas the night-time LF/HF ratio was significantly higher.

CONCLUSION

Although Holter ECG is not a diagnostic tool for cardiac sarcoidosis, the HRV parameters, especially the night-time LF/HF values, may demonstrate increased sympathetic activation in patients with sarcoidosis.

Assessment of left ventricular systolic and diastolic dyssynchrony with tissue Doppler echocardiography in patients with heart failure and narrow QRS complex

AIM

Cardiac dyssynchrony is a well known entity in patients with wide QRS complex (>120 ms). Dyssynchrony may also cause ventricular dysfunction in heart failure patients with narrow QRS complexes. In the study, the presence and extent of cardiac dyssynchrony were investigated in patients with heart failure both with narrow and wide QRS complexes using tissue Doppler echocardiography (TDE).

METHODS

Forty-nine patients with heart failure, were included to the study. The first group of 30 patients with a QRS duration of <120 ms (23M; mean age, 64±10.1 years) and the second group consisted of 19 patients with a QRS duration of >120 ms (12M; mean age, 65±11.6 years). In order to examine cardiac synchronization, TDE was performed. Systolic and diastolic intraventricular dyssynchrony and interventricular dyssynchrony were calculated. In order to define systolic and diastolic dyssynchrony, intraventricular delay was accepted as >60 ms, and interventricular delay was accepted as >40 ms.

RESULTS

Left ventricular systolic dyssynchrony was detected in 18 patients (60%) within the narrow QRS group and in 18 patients (94%) within the wide QRS group. Interventricular dyssynchrony was detected in 17 patients (56%) within the narrow QRS group and in 18 patients (94%) within the wide QRS group. For systolic dyssynchrony, correlations existed between intraventricular delay and QRS duration (r=0.48), left ventricular end diastolic diameter (r=0.62), left ventricular end systolic diameter (r=0.61), and EF (r=-0.63). Similarly, correlations existed between interventricular delay and QRS duration (r=0.58), left ventricular end diastolic diameter (r=0.65), left ventricle end systolic diameter (r=0.64), and EF (r=-0.64).

CONCLUSION

The present study suggested that systolic or diastolic dyssynchrony exists despite normal levels of QRS duration.