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Tolga Aksu,1 Tumer Erdem Guler,1 Ebru Golcuk,2 Kazim Serhan Ozcan,1 Ismail Erden1 1Department of Cardiology, Derince Training and Research Hospital, Kocaeli, Turkey; 2Department of Cardiology, School of Medicine, Koç University, Istanbul, Turkey Abstract: Idiopathic ventricular tachycardia (IVT) is an important type of arrhythmia, which has distinct electrocardiographic features and treatment options. Most of the cases originate from right ventricular outflow tract and less frequently from the left ventricular outflow tract. IVTs originating from mitral annulus are rare, and little is known about the efficacy of radiofrequency catheter ablation in this form. We hereby present a rare case of IVT arising from posterior mitral annulus. The electrocardiographic, electrophysiological, and electroanatomical characteristics of this tachycardia are discussed. Keywords: radiofrequency, ventricular arrhythmia

OBJECTIVE: The difference of the conduction velocity (CV) around the tricuspid valve annulus between the counter-clockwise (CCW) atrial flutter and the clockwise (CW) atrial flutter has not been well clarified. This study was undertaken to evaluate the CV and the conducting area (CA) per millisecond around the tricuspid valve annulus using the electroanatomical mapping. METHODS: The electroanatomical mapping was performed during the tachycardia for 30 consecutive patients (mean age: 61±16 years) with isthmus-dependent atrial flutter (CCW, 25; CW, 5). We measured the CV and the CA of five divided areas of the right atrium, that is, upper septum (US), lower septum (LS), isthmus (I), upper lateral wall (UL) and lower lateral wall (LL) using the novel measurement method in the isochronal map. Statistical differences of these data between the two groups were assessed by the Student's t-test and one-way analysis of variance methods. RESULTS: In total, the CV of the LS was significantly slower than other areas (m/sec: US, 0.57±0.18; LS, 0.43±0.18; UL, 0.60±0.26; LL, 0.53±0.20; I, 0.50±0.17; p<0.05) and the CA of the US and UL were significantly larger than other areas (mm2/sec: US, 34.5±16.2; LS, 16.2±9.5; UL, 40.0±14.1; LL, 27.0±17.0; I, 16.8±8.5; p<0.0001). There was no significant difference between the CCW and the CW atrial flutters in terms of the CV and the CA of equally divided five areas. CONCLUSION: In both of the CCW and the CW atrial flutters, the CV of the LS was significantly slower than other areas and the CA of the lower atrium was significantly smaller than the upper atrium. [ABSTRACT FROM AUTHOR]

Tolga Aksu, Tumer Erdem Guler, Ebru Golcuk, Ismail Erden, Kazim Serhan Ozcan Department of Cardiology, Kocaeli Derince Education and Research Hospital, Derince, Kocaeli, Turkey Abstract: Radiofrequency catheter ablation of the slow pathway is considered to be the treatment of choice for patients with atrioventricular nodal reentrant tachycardia. We report a 34-year-old female with mirror image dextrocardia due to unilateral pulmonary agenesis who underwent successful slow pathway ablation for typical atrioventricular nodal reentrant tachycardia. Using contrast injection, cardiac anatomy was identified in a short time and successfully ablated. Keywords: dextrocardia, AVNRT, ablation, pulmonary agenesis

Tolga Aksu,1 Tumer Erdem Guler,1 Ebru Golcuk,2 Kazim Serhan Ozcan,1 Ismail Erden1 1Department of Cardiology, Derince Training and Research Hospital, Kocaeli, Turkey; 2Department of Cardiology, School of Medicine, Koç University, Istanbul, Turkey Abstract: Electrical storm (ES) is associated with a poor prognosis if it occurs in the early postinfarction period (within 4 weeks). There are limited data on the efficacy and safety of catheter ablation in the early period. In the patients with postinfarction cardiomyopathy, ventricular tachycardia (VT) is usually caused by re-entry through slowly conducting tissue within areas of a myocardial scar, whereas for the early postinfarction period, the underlying mechanism of ES is not fully understood. We report a case of ES for which macroreentry was excluded as a mechanism of VT because of the clinical and electrophysiological properties of the tachycardia. The tachycardia was terminated by focal radiofrequency catheter ablation of the earliest site. The total procedure time was only 35 minutes. During a 12-month follow-up period, the patient has remained free of monomorphic VT episodes. On the basis of this case, we aimed to discuss the underlying mechanism of ES in the early postinfarction period and to evaluate the role of radiofrequency catheter ablation as a primary approach for treating ES. Keywords: ablation, electrical storm, ventricular tachycardia

Premature ventricular contractions (PVCs) are usually regarded as benign in the absence of structural heart disease. However, frequent PVCs can lead to depressed LV function, called PVC-induced cardiomyopathy and can be reversible after suppression of PVCs. On the other hand, PVCs can be a part of underlying structural heart disease and may be linked to increased risk of sudden death. In this work, we reviewed the current literature on PVC-induced cardiomyopathy based on a case presentation.

A case of long-standing persistent atrial fibrillation (LPAF) that underwent hybrid treatment combining transvenous cryothermal and radiofrequency (RF) energy is described in the present report. Complex fractionated atrial electrogram (CFAE) maps before and after cryoablation revealed not only pulmonary vein isolation (PVI), but also a large antral ablation of CFAEs. Following cryoablation, a severe reduction in remote left atrial CFAE area was observed.

Objective: Histologic plaque characteristics may influence the hemodynamic effect generated by physiologically significant unstable coronary lesions where plaque content and surface related factors are expected to contribute to the maximum translesional pressure drop. In this study, we aimed to identify local lesion specific virtual histological characteristics that may potentially affect hemodynamic outcome measures., Methods: Forty-eight consecutive patients with non-ST-elevation acute coronary syndrome (NSTEACS) having paired hemodynamic and morphological data were enrolled. A dual sensor guide-wire was used for the assessment of fractional flow reserve (FFR) and stenosis resistance (HSR) in the culprit vessel. Virtual histology intravascular ultrasound imaging was performed after obtaining hemodynamic data., Results: In a hemodynamically significant lesion subset (FFR<0.75 [n=34]), after controlling for lesion length, MLA and coronary artery compliance, FFR correlated with necrotic core (NC) area (r=-0.423, p=0.028) at MLA and NC volume (r=-0.497, p=0.008) and dense calcium (DC) volume (r=-0.332, p=0.03) across the entire lesion segment. Likewise, NC (r=-0.544, p=0.005) and DC (r=0.376, p=0.03) areas at MLA and NC (r=0.545, p=0.005) and DC (r=0.576, p=0.003) volumes across the entire lesion segment were associated with HSR in the hemodynamically significant lesion group (HSR>0.80 [n=33]). However, no correlation has been observed between intracoronary hemodynamic end-points and plaque components in hemodynamically insignificant lesions., Conclusions: This study demonstrated that for a given coronary stenosis geometry and arterial compliance, plaque composition may influence hemodynamic outcome measures in functionally significant stenoses in patients with NSTEACS., (Copyright © 2015. Published by Elsevier Ireland Ltd.)

Objective: Microvolt T-wave Alternans (TWA) is associated with abnormal repolarization and predicts arrhythmic mortality in patients with previous myocardial infarction (MI). Infarct tissue size and heterogeneity characterized by cardiac magnetic resonance (CMR) has been shown to be associated with arrhythmogenic substrates and sudden cardiac death. Although both delayed enhancement-CMR (de-CMR) and TWA are useful in risk stratification of post-MI patients with preserved left ventricular function, the relationship between scar size and TWA has not studied yet. In this study, we aimed to study the relation between TWA and scar size and characteristics assessed with CMR in post-MI patients (pts) with relatively preserved systolic function presented with nonsustained VT., Methods: This observational cross-sectional study was enrolled 36 post-MI patients with mild-systolic dysfunction and non-sustained ventricular tachycardia. Eight pts were excluded. Both TWA and contrast enhanced CMR were performed. Left ventricular ejection fraction (LVEF), dense scar, peri-infarct zone and total scar masses were assessed and these values to left ventricular (LV) mass ratios were calculated. Infarct ratios and characteristics were determined and compared among patients with negative TWA and those with positive TWA., Results: For the positive (n=12) vs. negative (n=16) TWA patients there were no significant difference between LVEF (44.9 ± 5.4% vs. 44.0 ± 3.2%, p=NS) and LV masses (121.89 ± 26.56 g vs. 106.14 ± 21.16 g, p=NS). The ratio of scar core to LV mass (3.37 ± 0.68% vs. 3.31 ± 1.01%, p=NS), peri-infarct zone to LV mass (23.61 ± 7.93% vs. 21.64 ± 9.08%, p=NS), total scar to LV mass (26.98 ± 7.86% vs. 24.96 ± 9.62%, p=NS) were all similar., Conclusion: There were no association between scar size and infarct heterogeneity and prevelance of TWA in post-MI patients with relatively preserved LVEF with non-sustained VT. Our data suggest that these two modalities may reflect different arrhythmogenic mechanisms in this cohort.

Atrioventricular nodal reentrant tachycardia (AVNRT) is the most frequent form of paroxysmal supraventricular tachycardia. Selective radiofrequency (RF) catheter ablation of the slow pathway is an ideal method for treatment of patients with AVNRT. Complete atrioventricular block is a rare but serious complication of RF ablation, and primarily occurs during or immediately after the procedure. We report on a 45-year-old woman who underwent successful ablation for symptomatic AVNRT at the age of 33. She presented with paroxysmal complete AV block, which developed twelve years after RF ablation of the slow pathway and a permanent DDD pacemaker was implanted. As seen in the case we report, complete AV block complicating RF ablation can occur years after the procedure.

Brugada syndrome is a genetic disease characterized by persistent or transient ST elevation in the right precordial electrocardiogram (ECG) leads with or without right bundle branch block. It represents an increased risk for sudden cardiac death despite a structurally normal heart. Brugada-type ECG can be unmasked and induced by several circumstances. We report on a 24-year-old male patient who experienced a syncopal episode and manifested Brugada type 1 ECG during a febrile state. His ECG changed to normal after treatment of fever. A single-chamber ICD was implanted to the patient because of syncope, fever-induced type I Brugada ECG pattern, and ventricular fibrillation during ajmaline challenge.

Background/aims: Endothelial dysfunction is an early and reversible feature in the pathogenesis of atherosclerosis. Coronary flow velocity reserve is a noninvasive test showing endothelial function of epicardial coronary arteries and coronary microcirculatory function. This study was designed to evaluate the carotid intima-media thickness and myocardial microvascular circulation in patients with non-alcoholic fatty liver disease., Materials and Methods: Twenty-four patients with non-alcoholic fatty liver disease and 28 healthy subjects were studied. According to the pathology of liver biopsies, patients with non-alcoholic fatty liver disease were divided into non-alcoholic fatty liver and nonalcoholic steatohepatitis groups. Coronary diastolic peak flow velocities were measured at baseline, and then dipyridamole infusion was measured by transthoracic Doppler echocardiography. The ratio of hyperemic to baseline diastolic peak velocities was calculated and the intima-media thicknesss of the carotid arteries were measured., Results: Baseline average diastolic peak and diastolic mean flow velocities were similar between non-alcoholic fatty liver disease patients and healthy subjects. However, hyperemic average diastolic peak and diastolic mean flow velocities were significantly lower in the patient groups compared to those in the controls (p=0.005 and p=0.002). Coronary flow velocity reserve was 1.65 ± 0.36 and 2.67 ± 0.81 in patients and healthy subjects, respectively (p < 0.001). The intima-media thickness was similar between the patients with non-alcoholic fatty liver disease and healthy subjects. The comparison of patients with non-alcoholic fatty liver and non-alcoholic steatohepatitis within the non-alcoholic fatty liver disease group with respect to coronary flow velocity reserve and intima-media thickness yielded no statistical differences., Conclusions: The present study showed that coronary flow velocity reserve, which establishes coronary microvascular and endothelial functions noninvasively, is significantly impaired in patients with non-alcoholic fatty liver disease. The impaired coronary flow velocity reserve-like early atherosclerotic changes may have value in the prediction of coronary artery disease in patients with non-alcoholic fatty liver disease.

Objective: The aim of this study was to investigate the additional value of single-photon emission computed tomography (SPECT) for patient staging compared to planar bone scanning in an unselected cohort of cancer patients., Methods: The study included 271 consecutive tumor patients in whom planar imaging and two-bed position SPECT of the spine and the pelvis had been performed. Retrospective image interpretation was performed independently for planar and SPECT scans. Findings were categorized as 'benign', 'equivocal', or 'malignant' on a lesion base, and as 'no metastatic disease', 'equivocal', or 'metastatic disease' on a patient base., Results: 447 lesions were detected by SPECT. Missing of lesions in planar images was rare (4.3% of all SPECT lesions). Planar findings differed from SPECT findings in 149 lesions (33.3%). Most of these 'inconsistent' lesions were rated as equivocal in the planar images but benign (14.5% of all lesions) or malignant (11.0%) by SPECT. On a patient base, 81.6% of patients with planar equivocal staging were classified as either benign (55.3%) or malignant (26.3%) by SPECT. Patients definitively staged as 'no metastatic disease' or 'metastatic disease' in planar images were staged differently by SPECT in only 3.7% of cases (up-staging in 2.6% and down-staging in 1.1%)., Conclusions: Single-photon emission computed tomography changed a definite staging as based on planar images in less than 4% of the patients. In patients with planar equivocal staging, however, SPECT allowed a definite diagnosis in more than 80% of these cases, and, thus, should be performed routinely in patients with equivocal findings.