Contrast-induced early repolarization pattern and ventricular fibrillation.

Malignant arrhythmias during coronary angiography consist a complication of the procedure. Clinicians should be aware that intracoronary infusion of contrast medium can lead to physiological changes that lower the ventricular fibrillation threshold.

Cardiac transplantation: towards a new noninvasive approach of cardiac allograft rejection.

INTRODUCTION: Cardiac allograft rejection (CAR) may occur after transplantation and remains silent, until hemodynamic deterioration takes place. Endomyocardial biopsy (EMB) is applied to early detect CAR. Although, flexible bioptoms have decreased the incidence of lethal complications, EMB remains an invasive procedure carrying risk of tamponade and permanent heart block. Therefore, a new non-invasive approach is needed. Areas covered: AlloMap molecular expression testing and graft-derived cell-free DNA (GcfDNA) test can be used as blood indices of acute and chronic CAR, respectively. Among diagnostic techniques, only echocardiography and cardiovascular magnetic resonance (CMR) have shown a strong correlation with EMB. Echocardiography is bedside, cost and time saving. However, the currently used indices are insensitive markers of CAR. Global longitudinal strain (GLS) can diagnose the subclinical CAR and be used together with EMB to monitor acute CAR. CMR can improve our diagnostic accuracy using T2STIR, T1, T2 mapping, early/late gadolinium enhancement and functional assessment. Expert commentary: A new non-invasive approach in asymptomatic transplanted patients should be based on a serial assessment of AlloMap, GcfDNA testing, echocardiographic and CMR indices that will guide the indication for EMB. In symptomatic patients immediate EMB is the approach of choice, since they have high likelihood for CAR.

Thyroid hormone signalling is altered in response to physical training in patients with end-stage heart failure and mechanical assist devices: potential physiological consequences?

OBJECTIVES: The present study investigated the potential of the failing myocardium of patients with ventricular assist devices (VAD) to respond to physiological growth stimuli, such as exercise, by activating growth signalling pathways. This may be of therapeutic relevance in identifying novel pharmacological targets for therapies that could facilitate recovery after VAD implantation. METHODS: Twenty-two patients bridged to heart transplantation (HTx) with VAD were included in the study. A group of patients underwent moderate intensity aerobic exercise (GT), while another group of patients did not receive exercise training (CG). Thyroid hormone receptor alpha1 (TRα1) protein and total (t) and phosphorylated (p) protein kinase B (Akt) and c-Jun N-terminal kinase (JNK) kinase signalling were measured in myocardial tissue by western blotting at pre-VAD and pre-HTx period. In addition, Thyroid hormone (TH) levels were measured in plasma. RESULTS: Peak oxygen consumption (VO2) at pre-HTx period was higher in patients subjected to training protocol [18.0 (0.8) for GT when compared with 13.7 (0.7) for CG group, P = 0.002]. N-terminal-prohormone of brain natriuretic peptide (NT-proBNP) levels were 1068 (148) for CG vs 626 (115) for GT group, P = 0.035. A switch towards up-regulation of physiological growth signalling was observed: the ratio of p-Akt/t-Akt was 2-fold higher in GT vs CG, P < 0.05 while p-JNK/t-JNK was 2.5-fold lower (P < 0.05) in GT vs CG, in pre-HTx samples. This response was accompanied by a 2.0-fold increase in TRα1 expression in pre-HTx samples with concomitant increase in circulating T3 in GT vs CG, P < 0.05. No differences in peak VO2, NT-proBNP, T3, TRα1, p/t-AKT and p/t-JNK were found between groups in the pre-VAD period. CONCLUSIONS: The unloaded failing myocardium responded to physical training by enhancing thyroid hormone signalling. This response was associated with an up-regulation of Akt and suppression of JNK activation.