Management of Tachycardia in Morbidly Obese Patients

Initial Assessment

Morbidly obese patients commonly have increased baseline heart rates, and physical examination often underestimates cardiac dysfunction, according to the American Heart Association 1, 2
Obtain a 12-lead ECG and chest radiograph for all severely obese patients with tachycardia to establish baseline cardiac status and rule out structural abnormalities, as recommended by the American College of Cardiology 1, 3
Evaluate for potential causes of tachycardia specific to obesity, including obesity cardiomyopathy, which is primarily diastolic dysfunction, but some patients exhibit both diastolic and systolic dysfunction, as noted by the American Heart Association 2, 3
Obstructive sleep apnea is common in morbid obesity and associated with arrhythmias, according to the American Academy of Sleep Medicine 4

Check for signs of right ventricular hypertrophy on ECG, which may indicate pulmonary hypertension, as suggested by the American College of Cardiology 5
Left bundle-branch block configuration is unusual in uncomplicated obesity and raises suspicion for coronary heart disease, according to the American Heart Association 5
Consider arterial blood gas measurement if hypoventilation or other pulmonary conditions are suspected, as recommended by the American Thoracic Society 6, 7
Functional exercise testing is preferred for cardiovascular risk assessment, though many morbidly obese patients cannot exercise due to weight or orthopedic issues, as noted by the American College of Sports Medicine 8

For refractory cases of tachycardia, consider cardioversion, and morbidly obese patients may require increased energy for cardioversion, as suggested by the American Heart Association 4

When using anticoagulation in morbidly obese patients with atrial fibrillation, low-molecular-weight heparin dosing should be based on total body weight, with twice-daily dosing preferred over once-daily, as recommended by the American College of Chest Physicians 8

Avoid underestimating cardiovascular risk in morbidly obese patients who appear otherwise healthy, as occult coronary heart disease is common, according to the American Heart Association 1, 2
Be aware that exertional dyspnea and lower extremity edema are nonspecific in obesity and may not indicate cardiac dysfunction, as noted by the American College of Cardiology 2
Remember that standard physical examination techniques may be less reliable in severely obese patients, as suggested by the American Heart Association 5