Sleep Disordered Breathing and Cardiovascular Diseases

Abstract

Sleep disordered breathing (SDB), which causes sleep deprivation, intermittent hypoxia, and negative intrathoracic pressure swings, can be accompanied by other harmful pathophysiologies relating to cardiovascular diseases (CVD), including sudden death, atrial fibrillation, stroke, and coronary artery disease leading to heart failure. Continuous positive airway pressure (CPAP) therapy for SDB has been reported to provide favorable effects such as lowered systemic blood pressure and improved endothelial function. However, in recent randomized controlled trials, CPAP has failed to demonstrate its beneficial prognostic impact on the primary or secondary setting of CVD. In this review article, we describe the characteristics of SDB complicated with CVD, the prognostic impacts of SDB in CVD, and the beneficial effects of CPAP on CVD.

Keywords: Atrial fibrillation; Cerebrovascular disease; Coronary artery disease; Heart failure; Sleep apnea syndrome.

Fig. 1.

Pathophysiology of the impact of sleep disordered breathing, OSA, on cardiovascular disease PAI-1, plasminogen activator inhibitor-1; ROS, reactive oxygen species; NO, nitric oxide; FMD, flow-mediated dilatation; IMT, intima-media thickness; PWV, pulse wave velocity; CAVI, cardio-ankle vascular index.

Fig. 2.

OSA OSA (downward arrow) is characterized by cessation or marked reduction of the airflow (airflow band) in the presence of respiratory effort (thorax and abdomen band), followed by arousal with breathing resumption.

Fig. 3.

OSA on treatment with positive airway pressure. CPAP provides continuous pressure throughout the respiratory cycle, preventing the pharynx from collapsing and thus suppresses cessation or reduction of airflow and desaturation.

Fig. 4.

Hypnogram shows an overview of the night's sleep, including SDB, sleep stage, heart rate, and oxygen saturation In the hypnogram of representative case, CPAP attenuates SDB, and improves both sleep quality and heart rate variation. CSA, central sleep apnea; OSA, obstructive sleep apnea; SpO2, oxygen saturation; AHI, apnea hypopnea index; REM, rapid eye movement.

Fig. 5.

CSA CSA (downward arrow) is characterized by cessation of both airflow (airflow band) and respiratory effort (thorax and abdomen band) during sleep. Cheyne–Stokes respiration is recognized as increasing and decreasing gradually repeated respiratory pattern.

Fig. 6.

Effect of CPAP on SDB and arterial blood pressure measured by the PTT method Improvement of SDB by CPAP leads to decreased PTT-based blood pressure and PTT index. AHI, apnea hypopnea index; SpO2, oxygen saturation; REM, rapid eye movement.