Heart : official journal of the British Cardiac Society
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Clinical Trial Controlled Clinical Trial
Impaired myocardial blood flow and coronary flow reserve of the anatomical right systemic ventricle in patients with congenitally corrected transposition of the great arteries.
To investigate myocardial blood flow of the morphological right systemic ventricle in unoperated patients with congenitally corrected transposition of the great arteries (CCTGA) by positron emission tomography (PET). ⋯ Blood flow measurements suggest that coronary reserve is decreased in the absence of ischaemic symptoms in patients with CCTGA. The global impairment of stress flow dynamics may indicate altered global vasoreactivity, and quantitative changes in microcirculation suggest that their role in the pathogenesis of systemic right ventricular dysfunction is important.
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Polymerase chain reaction (PCR) allows detection of Trypanosoma cruzi in blood throughout the course of Chagas' disease. ⋯ In a cohort of seropositive individuals, patients with T cruzi DNA detected by PCR and male patients were at higher risk of progression. These results highlight the importance of T cruzi in the pathophysiology of chronic cardiomyopathy.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparison of monophasic and biphasic shocks for transthoracic cardioversion of atrial fibrillation.
To compare the efficacy of cardioversion in patients with atrial fibrillation between monophasic damped sine waveform and rectilinear biphasic waveform shocks at a high initial energy level and with a conventional paddle position. ⋯ A protocol using monophasic waveform shocks in a 200-360 J sequence has the same efficacy (90%) as a protocol using rectilinear biphasic waveform shocks in a 120-200 J sequence. This equal efficacy is achieved with a significantly lower mean delivered energy level using the rectilinear biphasic shock waveform. The potential advantage of lower energy delivery for cardioversion of atrial fibrillation needs further study.
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Randomized Controlled Trial Clinical Trial
Acetylcholinesterase inhibition with pyridostigmine improves heart rate recovery after maximal exercise in patients with chronic heart failure.
To characterise the effects of acetylcholinesterase inhibition with pyridostigmine on parasympathetic tone in patients with chronic heart failure (CHF). ⋯ Acetylcholinesterase inhibition with pyridostigmine increased heart rate recovery at one minute but not at three minutes after exercise. A specific effect of pyridostigmine on heart rate one minute after exercise suggests that pyridostigmine augments parasympathetic tone in patients with CHF.