Computed tomography is important in appropriately diagnosing patients with third-degree atrioventricular block and second-degree atrioventricular block but not Wenckebach type.

PURPOSE: To evaluate CT utility for detection of cardiac or lung abnormalities in the diagnosis of organic cardiac disease in subjects with second- or third-degree atrioventricular block (AVB) excepting Wenckebach type.

MATERIALS AND METHODS: A total of 50 consecutive patients (25 male; 64±15years) with de novo third- or second-degree AVB underwent both TTE and a combination of cardiac and chest 320 slice CT (Aquilion one, Toshiba Medical) and were retrospectively analyzed. The presence of focal left ventricular (LV) wall thinning and thickening was evaluated on both TTE and cardiac CT. We evaluated the presence of significant coronary artery stenosis, focal late enhancement (LE) in LV myocardium, significant-sized (>10mm) lymph nodes in hialus or mediastinum and/or typical lung nodules for sarcoidosis on CT.

RESULTS: Abnormalities for 26%, 30%, and 36% of patients were demonstrated on TTE, cardiac CT, and a combination of cardiac and chest CT, respectively. 12% and 18% patients who did not exhibit cardiac abnormalities on TTE, revealed abnormalities on cardiac CT, or a combination of cardiac and chest CT, respectively. 36% patients had organic cardiac diseases. Sensitivities for detection of organic cardiac disease were significantly greater when cardiac and chest CT were combined than TTE alone (P<0.01).

CONCLUSIONS: Approximately one third of patients with third- or second-degree AVB had organic cardiac diseases. For detection of cardiac and chest abnormality and correct diagnosis of organic cardiac disease in patients with third- or second-degree AVB, TTE is not sufficient on its own. CT or a combination of TTE and CT are required.