Electrocardiographic impacts of lung resection.

ABSTRACT

INTRODUCTION: Electrocardiographic (ECG) changes accompanying lung resection have not been well investigated previously in a large controlled series of human adults. Thus, our current investigation was undertaken for a better understanding of the ECG changes associated with lung resection. MATERIALS AND METHODS: Medical records of 117 patients who underwent lung resection (segmentectomy, lobectomy, or pneumonectomy) were reviewed. Their clinical course and ECGs were compared during early, intermediate and late postoperative course (<1 month, 1 month to 1 year and >1 year post-op respectively). RESULTS: Patients in the acute postoperative phase had higher heart rate, increased maximum P-duration and P-dispersion, increased incidence of atrial arrhythmias and frequent ST-T changes. P-vector and QRS-vector were significantly affected after the lung resections; the correlation being most consistent between the anatomical displacements and the QRS-vector in the majority of patients. The axial shifts also demonstrated a characteristic temporal relationship after left pneumonectomy (a leftward deviation in the acute, normal or slight rightward deviation in the intermediate and a rightward deviation in the late postoperative course). The precordial R/S transition is often affected due to the mediastinal shifts and the ECGs in patients after left lung resection may simulate acute anteroseptal myocardial infarction due to a delayed R/S transition. CONCLUSION: The understanding and recognition of the expected ECG findings after lung resection are imperative to avoid confusing these changes with other acute cardiopulmonary events which would prevent unnecessary further investigational work-up. These ECG changes are often dynamic and may bear a temporal relationship to the dynamic post-surgical changes in the thoracic anatomy.