A case report of upgrading to cardiac resynchronization therapy in a patient with congenitally corrected transposition of great arteries and dextrocardia.

Background: Congenitally corrected transposition of the great arteries (CCTGA) is a rare congenital heart anomaly. Physiological correction may be associated with a long pre-symptomatic period in many patients and delayed accidental diagnosis. Additional related congenital malformations may increase the complexity of cardiac interventions. Case summary: A 59-year-old man with known dextrocardia, situs viscerum inversus, and CCTGA was scheduled for upgrading of a dual-chamber pacemaker to cardiac resynchronization therapy to treat heart failure related to a progressive systolic dysfunction of the systemic right ventricle (RV). Because of the specific anatomy of this patient, the therapeutic procedure was complicated by the cannulation of the Marshall vein. Nevertheless, the left ventricular lead was successfully implanted into the coronary sinus lateral branch. At the 3-month follow-up, the patient remarkably reported a significant functional improvement, despite no favourable reverse remodelling of the systemic RV. Discussion: Upgrade of a pacemaker to biventricular pacing was feasible in this patient, who had CCTGA and dextrocardia, which resulted in symptomatic improvement at follow-up. Pre-implant contrast cardiac computed tomography angiography was essential for visualizing the venous-specific anatomy in this patient, who suffered from congenital heart disease. Conduction system pacing represents a potential alternative for the patient to prevent or treat pacing-related heart failure.

Capture threshold of bipolar and unipolar pacing of left ventricle via coronary sinus branch: longitudinal study.

Introduction: The aim of this paper is to first monitor the changes in the capture threshold of endovascularly placed leads for left ventricle pacing, second to compare the pacing configurations, and third to verify the effect of Steroid elution for endovascular leads. Sample and Method: The study included 202 consecutive single centre patients implanted with the Quartet™ lead (St. Jude Medical). The capture threshold and related lead parameters were tested during implantation, on the day of the patient's discharge, and 3, 9, and 15 months after implantation. The electrical energy corresponding to the threshold values for inducing ventricular contraction was recorded for subgroups of patients with bipolar and pseudo-unipolar pacing vectors and electrodes equipped with and without a slow-eluting steroids. The best setting for the resynchronization effect was generally chosen. Capture threshold was taken as a selection criterion only if there were multiple options with (expected) similar resynchronization effect. Results and Discussion: The measurements showed that the ratio of threshold energies of UNI vs. BI was 5× higher (p < 0.001) at implantation. At the end of the follow-up, it dropped to 2.6 (p = 0.012). The steroid effect in BI vectors was caused by a double capture threshold in the NSE group compared to the SE group (p < 0.001), increased by approximately 2.5 times (p < 0.001). The study concludes that after a larger initial increase in the capture threshold, the leads showed a gradual increase in the entire set. As a result, the bipolar threshold energies increase, and the pseudo-unipolar energies decrease. Since bipolar vectors require a significantly lower pacing energy, battery life of the implanted device would improve. When evaluating the steroid elution of bipolar vectors, we observe a significant positive effect of a gradual increase of the threshold energy.

Triple Combination with Direct Acting Antivirals in the Treatment of Hepatitis C Does not Prolong the QT Interval.

AIMS: Antiviral drugs are considered as potentially cardiotoxic, due to prolongation of QT interval which may affect incidence of severe ventricular arrhythmias. The main aim of this retrospective study was to assess the influence of treatment by three antiviral drugs on QT interval and to find patients who are at an increased risk of developing malignant ventricular arrhythmias. METHODS: The study included 23 patients (14 men, 9 women) who were treated with a combination of interferon alpha, ribavirin, and an NS3/4A protease inhibitor. The parameters from the 12 leads electrocardiograms were evaluated before treatment, and then 3 ± 1 and 6 ± 1 months after treatment. RESULTS: Heart rate (HR) 69 ± 12 / min and corrected QT interval (QTc) 412 ± 35 ms were obtained before the treatment and there was not observed a significant prolongation of intervals after 3 months (HR 72 ± 11 / min, QTc 412 ± 33 ms) and after 6 months (HR 64 ± 12 / min, QTc 405 ± 28 ms) respectively. In total QTc interval was prolonged from the baseline in 53% and in 43% of the patients 3 months respectively 6 months after treatment. A QTc prolongation over of 450 ms and new treatment-related repolarization change was noted in 1 (4%) patient. CONCLUSION: The study demonstrates that a combination therapy of 3 antiviral drugs does not significantly prolong the QTc interval and does not cause severe pathological changes on the ECG. Patients undergoing this treatment are not at risk of developing heart disease as an undesirable side effect.

Right heart ventricle myocarditis induced by pulmonary thrombembolism.

Deep venous thrombosis and pulmonary thrombembolism are referred to as venous thrombembolism. Pulmonary thrombembolism affects the right ventricle. Two morphologically and clinically distinct conditions are distinguished according to change of blood pressure and speed of blood pressure increase in the pulmonary artery - acute and chronic cor pulmonale. Acute cor pulmonale develops during rapid increase (within seconds) of blood pressure in the pulmonary artery. Morphologically, the condition leads to dilatation of the right ventricle and clinically to sudden cardiac death or severe circulatory instability. Chronic cor pulmonale represents myocardial hypertrophy of the right ventricle as a response to the gradually increasing pressure in the pulmonary artery. Herein, we demonstrate a rare case report of right ventricular myocarditis in a 51-year-old woman with pulmonary thromboembolism and morphological signs of chronic pulmonary hypertension. This non-infectious myocarditis is histologically characterized by myocardial damage (myocytolysis) and dominant histiocytic and neutrophil infiltration accompanied by scanty T-lymphocytes. These inflammatory changes differ from those associated with myocardial infarction. The possible pathological mechanisms of right ventricular myocarditis induced by pulmonary thrombembolism are discussed.