Reversible severe pulmonary hypertension triggered by atrioventricular dyssynchrony in complete heart block: a case report

BACKGROUND: Complete heart block (CHB) is commonly encountered in older adults, yet its hemodynamic consequences extend beyond bradycardia and reduced cardiac output. Severe pulmonary hypertension (PH) secondary to atrioventricular (AV) dyssynchrony is exceedingly rare, particularly in patients with preserved left ventricular systolic function. Recognizing reversible PH due to rhythm disturbances is essential in the geriatric population where symptoms are often nonspecific. CASE PRESENTATION: An 86-year-old man presented with progressive fatigue, orthopnea, and presyncope. Echocardiography revealed severe PH with an estimated pulmonary artery systolic pressure (PASP) of 120 mmHg, preserved left ventricular ejection fraction (LVEF) of 60%, marked left atrial dilation, right ventricular enlargement, and moderate diastolic tricuspid regurgitation (TR). A dual-chamber pacemaker was implanted urgently, resulting in a rapid decline in PASP to 75 mmHg within 24 h, with a further decrease to 40 mmHg by two weeks. Structural cardiac improvements were sustained at one-year follow-up. CONCLUSIONS: This case highlights a rare and potentially reversible form of PH possibly triggered by AV dyssynchrony in an older adult with CHB. Diastolic TR may serve as a diagnostic clue, and restoration of AV synchrony was associated with rapid improvement in pulmonary pressures. These findings highlight the importance of considering arrhythmia-related reversible PH in elderly patients with cardiopulmonary symptoms and preserved systolic function.