Nitrates in Right-Sided Heart Failure: Contraindicated
Nitrates are contraindicated in right-sided heart failure and right ventricular infarction due to the risk of severe, potentially fatal hypotension. 1
Critical Contraindication
The use of nitrates in patients with right ventricular infarction is explicitly contraindicated (Class III recommendation) by the American Heart Association. 1 This contraindication exists because:
Right ventricular function is critically preload-dependent - the right ventricle requires adequate filling pressures to maintain cardiac output. 2
Nitrates cause venodilation and reduce preload - this mechanism, while beneficial in left-sided heart failure, can precipitate cardiogenic shock in right ventricular failure by dropping filling pressures below the critical threshold needed for right ventricular output. 2, 3
Severe life-threatening hypotension or death may occur when nitrates are used in patients with acute inferior myocardial infarction associated with right ventricular dysfunction or infarction. 3
Standard Management of Right Heart Failure
The appropriate treatment approach for right-sided heart failure is fundamentally different from left-sided failure:
Aggressive fluid resuscitation is the cornerstone - maintaining adequate preload is essential for right ventricular output. 2
Avoid preload-reducing agents - this includes diuretics, nitrates, or any maneuvers that decrease preload. 2
Even minor preload reduction can be catastrophic - something as simple as vagal stimulation from bladder catheter insertion can acutely decrease preload and precipitate cardiogenic shock. 2
Inotropic support may be needed - agents that improve contractility without excessive preload reduction are preferred. 2
Newer therapies show promise - inhaled nitric oxide (which acts locally in the pulmonary vasculature without systemic preload reduction) and intravenous vasopressin have demonstrated benefit in acute right ventricular failure. 2
Clinical Pitfall to Avoid
The most dangerous error is applying left-sided heart failure management principles to right-sided failure. While nitrates are first-line therapy for acute left heart failure and pulmonary edema 1, 4, they represent a life-threatening intervention in right ventricular failure due to the opposite hemodynamic requirements of these two conditions.