BACKGROUND The left and right atria have different susceptibilities toward developing arrhythmias, with left atrial arrhythmias more commonly observed. To understand the molecular basis for such differences, we catalogued micro (mi)RNA and mRNA expression differences by next generation sequencing. METHODS AND RESULTS Four human left-right atrial pairs were subjected to whole-genome expression...

The cellular electrophysiologic and structural characteristics of arrhythmic and non-arrhythmic atria isolated from feline hearts with spontaneously occurring cardiomyopathy were studied. The animals were divided into three groups according to the degree of left atrial enlargement: mild (group I), moderate (group II), and severe (group III). The right atria were of relatively normal size. Micro...

Atrial natriuretic peptide is a potent diuretic hormone secreted by the atria in response to volume expansion. We examined the effect of resting tension on atrial natriuretic peptide secretion by rat atria superfused in vitro. Left atria were hooked between an electrode and force transducer and superfused with medium 199. The atria were studied at a pacing frequency of 0 or 3 Hz. Atrial natriur...

patients with valvular heart disease suffer from atrial fibrillation for more than 12 months after valve surgery and have a low probability of remaining in sinus rhythm. we performed an intra-operative procedure similar to surgical maze ііі procedure for conversion of this arrhythmia to sinus rhythm. we did this study to evaluate the efficacy of this procedure to restore the sinus rhythm in pat...

right atrial dilation due to left heart disease is a common complication among adults. the present review aimed to describe a case of massively dilated right atrium in a female patient presenting with valvular heart disease and no atrial fibrillation. the results of chest x-ray revealed a large opacity filling the lower right hemithorax, falsely interpreted as a mediastinal mass. during the tra...

OBJECTIVE Our goal was to study rate adaptation of atrial action potentials in non-steady and steady states to further our understanding of mechanisms determining inducibility and stability of atrial fibrillation. METHODS We used standard microelectrode techniques to examine the characteristics of steady-state action potentials paced at regular cycle lengths (CL) and of nonsteady-state action...

An imaging system for di-4-ANEPPS (4-[beta-[2-(di-n-butylamino)-6-naphthylvinyl]pyridinium]) voltage-sensitive dye recordings has been adapted for recording from an in vitro mouse heart preparation that consists of both atria in isolation. This approach has been used to study inter- and intra-atrial activation and conduction and to monitor action potential durations (APDs) in the left and right...

  The effect of different doses (1-50 µ M) of imipramine (IMI) and desipramine (DES) on the rate and force of contraction of isolated rat atria was studied. IMI and DES produced a dose-dependent increase in force of contraction (31- 94% for IMI and 35-118% for DES). Pretreatment of rats with reserpine (5 mg/kg) on the isolated atria with propranolol (1 µ g) inhibited the positive ionotropic eff...

Lysophosphatidylcholine (LPC) is an endogenous phospholipid released from the cell membrane during ischemia, and it has potent cardiac effects, including inhibition of atrial natriuretic peptide (ANP) release. The aim of this study was to investigate the effects of LPC on hemodynamics and ANP release in hypertrophied atria and to define its mechanism. Isolated, perfused, beating, hypertrophied ...