ObjectivesThe predictors of pacing-induced cardiomyopathy (PICM) for complete atrioventricular block (CAVB) have not yet been defined. The aim of this study was to investigate the major determinant of the occurrence of PICM.SettingThis is a multicentre, retrospective analysis of CAVB from tertiary referral centres in Daejeon, South Korea.ParticipantsA cohort of 900 consecutive patients with an implanted pacemaker was collected from December 2001 to August 2015. Of these, a total of 130 patients with CAVB with pacing-dependent rhythm who underwent ECG and echocardiogram before and after implantation were analysed for the occurrence of PICM.Outcome measuresCox proportional hazards models evaluated the determinant of PICM by ECG, device parameters and echocardiogram over a mean of 4.5 years.ResultsPICM was observed in 16.1% (n=21) of all patients with CAVB (age, 64±11 years; male, 36.2%). The preimplant left ventricular (LV) ejection fraction (66%±9% vs 66%±8%) and non-apical pacing (40.4% vs 33.3%) were similar; however, the native QRS duration (124±34 ms vs 149±32 ms) and the paced QRS duration (pQRSd) (139±29 ms vs 167±28 ms) were significantly different between the two groups. The postimplant LV ejection fraction (61%±7% vs 31%±8%) was also significantly different at the end of follow-up. A pQRSd significantly correlated with PICM (HR 1.05, 95% CI 1.02 to 1.09, P=0.001). A pQRSd with a cut-off value of above 140 ms had a sensitivity of 95% while a pQRSd with a cut-off value of above 167 ms had a specificity of 90% for PICM.ConclusionIn patients with CAVB with pacing-dependent rhythm, regardless of the pacing site, the pQRSd is a major determinant of the occurrence of PICM.

Background and Objectives Cardiac myxoma is the most frequent benign cardiac tumor that can result in cardiac and systemic symptoms. We investigated clinical and echocardiographic characteristics of patients with cardiac masses suggesting myxoma. Methods We investigated 265 consecutive patients with an echocardiographic diagnosis of cardiac myxomas in 4 teaching hospitals in Korea. Results The mean age was 61±16 years and 169 patients (63.8%) were female. The most frequent referral reason for echocardiography was an evaluation of cardiac symptoms (43.4%). Tumors were incidentally detected in 82 patients (30.9%). Left atrium (LA) was the most frequently involved site (84.5%) and 19 patients (7.2%) had non-atrial tumors. The mean tumor size was 38.7×26.0 mm (range, 4–96 mm). Of 186 patients (70.2%) who had pathological diagnosis, 174 (93.5%) were confirmed with myxoma, 8 (4.3%) with other tumors and 4 (2.2%) with thrombi. Compared to myxoma, smaller size (20.4×12.6 mm vs. 41.4×27.6 mm, p<0.01) and non-LA location (87.5% vs. 10.5%, p<0.001) were associated with non-myxoma tumors, and more frequent atrial fibrillation (AF, 75.0% vs. 7.0%, p<0.001) and larger LA diameter (55.0±14.6 mm vs. 41.3±7.7 mm, p=0.001) were related to thrombi. Conclusions Of 265 patients with an echocardiographic diagnosis with cardiac myxomas, 174 (65.7%) were surgically confirmed with myxomas. Compared with cardiac myxoma, other tumors were smaller and more frequently found in non-atrial sites. Thrombi were associated with AF and larger LA diameter.

Background/AimsScrub typhus is known as a self-limited infectious disease. Cardiac complication is uncommon and usually not life-threatening. Until now, few cases of fulminant myocarditis by scrub typhus have been reported. So, we investigated incidence and predictors of acute myocarditis in severe scrub typhus.MethodsWe retrospectively reviewed 89 patients among 91 scrub typhus confirmed patients who examined an echocardiogram and cardiac biomarkers from 2005 to 2015 in the intensive care unit at our hospital. We excluded two patients who didn’t have electrocardiography. Patients were divided into two groups and compared between scrub typhus with (n = 13) and without (n = 76) acute myocarditis. ResultsAge, sex, and underlying diseases were similar between the groups. The existence of eschar and duration of general ache and fever were similar between the groups. However, patients with acute myocarditis had more elevated total bilirubin, high incidence of ST elevations and paroxysmal atrial fibrillation (PAF) than those without acute myocarditis. Receiver operating characteristic analysis showed that the PAF was a predictor of myocarditis with a sensitivity of 70% and specificity of 84%. Predictive power of combination of ST-segment elevation and PAF was significantly associated with myocarditis in the multivariate analysis (odds ratio, 1.57; 95% confidence interval [CI], 1.21 to 11.7; p = 0.041) and area under the curve was 0.947 (95% CI, 0.878 to 0.983; p < 0.001).ConclusionsAcute myocarditis with scrub typhus may be more common than previously reported. Patients with high bilirubin and PAF are at increased risk of acute myocarditis with scrub typhus. These patients warrant closer follow-up and echocardiogram would be needed.

Primary cardiac lymphoma (PCL) is an extranodal non-Hodgkin's lymphoma exclusively located in the heart and/or pericardium. It is rare in immunocompetent patients and represents 1.3% of primary cardiac tumors and 0.5% of extranodal lymphomas. The clinical behavior is aggressive and the early symptoms are cardiac failure, syncope, arrhythmia, or pericardial effusion. Although echocardiography, computed tomography (CT) scan, magnetic resonance image (MRI) are the mainly used imaging techniques to detect cardiac tumors, pathologic examination is always required to confirm the diagnosis. Diagnosis of PCL is difficult due to non-specific clinical manifestations and requires invasive approach to get histopathologic evidence. While surgery with systemic chemotherapy or in combination with irradiation has been attempted, the only effective treatment is chemotherapy. However, the prognosis remains poor. We report on a 42-year-old woman who is diagnosed histopathologically as PCL by cardiac catheterization assisted percutaneous endomyocardial biopsy and treated successfully by anthracycline based chemotherapy.

PurposeThe effect of radiofrequency catheter ablation (RFCA) on left atrial (LA) volume and function in patients with paroxysmal atrial fibrillation (PAF) has not been extensively studied. The aim of this study was to evaluate the long-term impact of RFCA on LA volume and function in patients with PAF.Materials and MethodsA total of 90 patients with drug-refractory PAF who had sinus rhythm on the initial echocardiogram were examined at baseline, 3 months and 1 year after ablation. We measured LA volume index, LA ejection fraction (LAEF; maximal-minimal LA volume/maximal LA volume), and LA active emptying fraction (LAAEF; mid-diastolic-minimal LA volume/mid-diastolic LA volume).ResultsAfter 12±1 months, 78 patients returned, and 61 patients (78%) had sinus rhythm. After 3 months, the LA maximal volume indices decreased (from 33±13 to 28±12 mL/m2; p<0.001). But, LAEF and LAAEF also decreased (from 48±13 to 39±12; p<0.001, from 27±13 to 19±11; p<0.001). After 1 year, LA volumes, LAEF, and LAAEF remained similar at 3 months. In patients without atrial fibrillation (AF) recurrence, LAEF and LAAEF decreased after 3 months (from 50±12 to 40±11; p<0.001, from 29±13 to 22±11; p<0.001) and did not change after 1 year. However, in patients with AF recurrence, those who did not have decreased levels after 3 months had significantly decreased after 1 year (from 43±14 to 34±11; p=0.026, from 22±12 to 15±10; p=0.012).ConclusionSuccessful RFCA of PAF decreased LA volume and function at 3 months. At one year, LA volume and function was remained unchanged in successfully ablated patients whereas LA function in patients with AF recurrence worsened.