Heart Failure
Cheyne-Stokes breathing (CSB)
Cheyne-Stokes breathing (CSB), which is commonly seen in patients with advanced congestive heart failure (CHF). CSB is a cyclic breathing pattern in which apnea is followed by gradually increasing then decreasing tidal volumes until the next apneic period. Patients with CHF have chronic hyperventilation with hypocapnia, which induces apnea during sleep when the partial pressure of carbon dioxide (PaCO2 falls below a certain level ("apneic threshold"). Apnea causes excessive buildup of C02 (hypercapnia); this stimulates a ventilatory response that overshoots (hyperpnea), causing the PaCO2, to again fall below the apneic threshold. This cycle of apnea and hyperventilation is further perpetuated by prolonged circulation time between the lungs and brain, which results in a discrepancy between PaC02 levels sensed by central chemoreceptors and PaC02 concentration in alveoli. CSB is also seen in neurologic disease (eg, stroke, brain tumors, traumatic brain injury) and is frequently a poor prognostic sign.
Management
In Heart failure, aldosterone is also produced in the myocardium and acts locally, leading to fibrosis and myocardial hypertrophy. The resulting cardiac remodeling worsens LV dysfunction
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Histologic findings:
In acute early phase: transudate accumulating in the alveolar lumen;
Hemosiderin- containing macrophages in the alveoli (ie, siderophages, or "heart failure cells") on Prussian blue stain are suggestive of prior episodes of pulmonary congestion and edema that arose due to CHRONIC left heart failure.
A number of drugs have been shown to improve mortality in patients with chronic heart failure:
No long-term reduction in mortality has been demonstrated for loop diuretics such as furosemide.
NICE issued updated guidelines on management in 2010, key points include: