Effect of Weight Loss on the ECG of Normotensive Morbidly Obese Patients

Background Morbid obesity produces a variety of ECGalterations, including leftward shifts of the P-wave, QRS, and T-waveaxes; disproportionately high frequencies of low QRS voltage; leftventricular hypertrophy and left atrial abnormality; and a highfrequency of T-wave flattening in the inferior and lateral leads. Thisstudy was designed to assess the effects of substantial weight loss onthe ECG in morbid obesity. Methods We performed aresting 12-lead ECG on 60 normotensive patients (48 women and 12 men; mean ± SD age, 37 ± 7 years), whose body weight was twice theirideal body weight prior to and at the time of maximum weight loss afterbariatric surgery. Results Mean weight decreased from136 ± 7 to 85 ± 3 kg. Weight loss produced significant decreasesin the frequencies of low QRS voltage; Romhilt-Estes point score ≥ 5points; SV 1 + RV 5 or V 6 > 35mm; RV 5 or V 6 > 26 mm; RaVL > 11 mm; RaVL≥7.5 mm; SaVR > 14 mm; P-terminal force more negative than−0.04 mm·s in lead V 1 ; and T-wave flattening inthe inferior, lateral, and inferolateral leads. Weight losssignificantly shifted the mean P-wave, QRS, T-wave axes rightward, andsignificantly reduced mean RaVL and mean SaVR voltage. Conclusion Substantial weight loss is capable of reversingmany of the ECG alterations associated with morbidobesity.