Continuous positive airway pressure ameliorates sleep-induced subclinical left ventricular systolic dysfunction: demonstration by two-dimensional speckle-tracking echocardiography.

AIMS: We hypothesized that continuous positive airway pressure (CPAP) therapy could improve sleep-induced left ventricular (LV) dysfunction in patients with obstructive sleep apnoea syndrome (OSA). The aim of this study was to investigate the effects of CPAP therapy on LV systolic dysfunction during overnight sleep in patients with OSA using two-dimensional speckle-tracking echocardiography (2DSTE). METHODS AND RESULTS: 2D LV short-axis and apical views were acquired before and immediately after overnight sleeping in 32 patients with OSA and normal LV ejection fraction. Using 2D strain software, three-principal strains were measured. In a subset of 14 OSA patients who received chronic CPAP therapy, identical measurements were repeated 3 months after the therapy. Although no significant changes in global radial and circumferential strain were noted, global longitudinal strain was significantly reduced after overnight sleeping (-19.1 +/- 2.0) compared with before sleep (-20.7 +/- 1.8, P < 0.001). After CPAP therapy, improvements in apnoea-hypopnoea index and minimal oxygen saturation were accompanied by the disappearance of longitudinal strain reduction during overnight sleep. CONCLUSION: Repetitive obstructive apnoea produces acute impairment of LV longitudinal function, suggesting the development of subendocardial ischaemia. CPAP therapy not only decreases the severity of OSA, but also ameliorates sleep-induced longitudinal LV dysfunction, which can be assessed by 2DSTE.

Cough syncope induced by gastroesophageal reflux disease.

A 52-year-old Japanese man was admitted to our hospital for evaluation of syncope and convulsions. An electrocardiogram on admission revealed normal sinus rhythm. However, after repeated bouts of coughing, the heart rate showed bradycardia associated with convulsion. He was diagnosed with cough syncope secondary to laryngopharyngitis, which was caused by gastroesophageal reflux disease (GERD). Once the patient was administrated lansoprazole (Takeda Pharmaceutical Co., Osaka, Japan) for GERD, the syncope disappeared. The causes of syncope are diverse and may manifest in disorders of different organ systems in the body. Therefore, clinicians should perform a careful whole body examination to obtain the correct diagnosis.

Overnight sleeping induced daily repetitive left ventricular systolic and diastolic dysfunction in obstructive sleep apnoea: quantitative assessment using tissue Doppler imaging.

AIMS: Although left ventricular (LV) diastolic dysfunction is frequently observed in patients with obstructive sleep apnoea (OSA), the effects of overnight sleeping on LV function remain unclear. The aim of this study was to determine acute effects of overnight sleeping on LV function in OSA patients. METHODS AND RESULTS: In 29 OSA patients with normal LVEF and 20 control subjects, tissue Doppler imaging (TDI), standard 2D, and Doppler echocardiography were acquired before and immediately after overnight sleep. Peak systolic (S'), early diastolic (E'), and late diastolic (A') annular velocities at septal and lateral corners were measured and averaged. The prevalence of hypertension was more often, LV mass index (102 +/- 16 vs. 89 +/- 18 g/m(2), P < 0.05) and left atrial volume index (25.3 +/- 4.0 vs. 22.3 +/- 4.4 mL/m(2), P < 0.05) were larger in OSA patients. Before sleeping, OSA patients had reduced E/A ratio suggesting impaired relaxation. Although no significant differences in S' were noted between the two groups, E' was lower and A' was higher in OSA patients compared with control subjects. Compared with before sleeping, S', E', and A' were significantly reduced after sleeping in both groups, but the per cent reduction of S' and A' was significantly larger in OSA patients. After overnight sleep, A wave velocity was also significantly reduced in OSA patients. A weak but significant correlation between per cent reduction of S'(A') and apnoea-hypopnoea index was noted. CONCLUSION: Overnight sleeping in OSA patients is associated with the development of subclinical systolic dysfunction and exaggerated diastolic dysfunction.