Publications

AIMS: Takotsubo syndrome (TTS) is an acute heart failure, typically triggered by high adrenaline during physical or emotional stress. It is distinguished from myocardial infarction (MI) by a characteristic pattern of ventricular basal hypercontractility with hypokinesis of apical segments, and in the absence of culprit coronary occlusion. We aimed to understand whether recently discovered circulating biomarkers miR-16 and miR-26a, which ...

The fast transient outward potassium current (Ito,f) plays a key role in phase 1 repolarization of the human cardiac action potential (AP) and its reduction in heart failure (HF) contributes to the loss of contractility. Therefore, restoring Ito,f might be beneficial for treating HF. The coding sequence of a P2A peptide was cloned, in frame, between Kv4.3 and KChIP2.1 genes and ribosomal skipping was confirmed by Western blotting. Typical Ito,f ...

BACKGROUND: Sympathetic activation in ischemic heart disease can cause lethal arrhythmias. These often are preceded by premature ventricular complexes (PVCs), which at the cellular level could result from delayed afterdepolarizations. OBJECTIVE: The purpose of this study was to identify and map vulnerable areas for arrhythmia initiation after myocardial infarction (MI) and to explore the link between PVCs and cellular events. METHODS: ...

Ischemic heart disease is the most common cause of lethal ventricular arrhythmias and sudden cardiac death (SCD). In patients who are at high risk after myocardial infarction, implantable cardioverter defibrillators are the most effective treatment to reduce incidence of SCD and ablation therapy can be effective for ventricular arrhythmias with identifiable culprit lesions. Yet, these approaches are not always successful and come with a ...

Spontaneous Ca2+ release (SCR) can cause triggered activity and initiate arrhythmias. Intrinsic transmural heterogeneities in Ca2+ handling and their propensity to disease remodeling may differentially modulate SCR throughout the left ventricular (LV) wall and cause transmural differences in arrhythmia susceptibility. Here, we aimed to dissect the effect of cardiac injury on SCR in different regions in the intact LV myocardium using cryoinjury ...

Cx43, a major cardiac connexin, forms precursor hemichannels that accrue at the intercalated disc to assemble as gap junctions. While gap junctions are crucial for electrical conduction in the heart, little is known about the potential roles of hemichannels. Recent evidence suggests that inhibiting Cx43 hemichannel opening with Gap19 has antiarrhythmic effects. Here, we used multiple electrophysiology, imaging, and super-resolution techniques to ...

Pulmonary hypertension is a complex disorder characterized by pulmonary vascular remodeling and right ventricular hypertrophy, leading to right heart failure. The mechanisms underlying this process are not well understood. We hypothesize that the structural remodeling occurring in the cardiomyocytes of the right ventricle affects the cytosolic Ca2+ handling leading to arrhythmias. After 12 days of monocrotaline-induced pulmonary hypertension in ...

KEY POINTS: Ventricular arrhythmias are a major complication after myocardial infarction (MI), associated with sympathetic activation. The structurally heterogeneous peri-infarct zone is a known substrate, but the functional role of the myocytes is less well known. Recordings of monophasic action potentials in vivo reveal that the peri-infarct zone is a source of delayed afterdepolarizations (DADs) and has a high beat-to-beat variability of ...

Rhythmic increases in intracellular Ca2+ concentration underlie the contractile function of the heart. These heart muscle-wide changes in intracellular Ca2+ are induced and coordinated by electrical depolarization of the cardiomyocyte sarcolemma by the action potential. Originating at the sinoatrial node, conduction of this electrical signal throughout the heart ensures synchronization of individual myocytes into an effective cardiac pump. Ca2+ ...