Which of the following is NOT seen in morbidly obese sleep apnea patient?
High-Yield Explanation
(C) Rt. Ventricular failure # Heart Failure leads to increased left ventricular (LV) filling pressure.> Resulting pulmonary congestion activates lung vagal irritant receptors, which stimulate hyperventilation and hypocapnia.> Superimposed arousals cause further abrupt increases in ventilation and drive PaCO2 below the threshold for ventilation, triggering a central apnea.> Central sleep apneas are sustained by recurrent arousals resulting from apnea-induced hypoxia and the increased effort to breathe during the ventilatory phase because of pulmonary congestion and reduced lung compliance.> Although central apneas have a different pathophysiology than obstructive apneas and are not associated with the generation of exaggerated negative intrathoracic pressure, they both increase sympathetic nervous system activity (SNA).> Consequent increases in blood pressure (BP) & heart rate (HR) increase myocardial O2 demand in the face of reduced supply.> This chain of events contributes to a pathophysiological vicious cycle.