The clinical course of sinus bradycardia and sinus tachycardia has been studied in 735 patients owith acute myocardial infarction admitted to a coronary care unit. Sinus bradycardia was considered to have occurred when two or more records showed sinus rhythm with a rate below 6o a minute, and sinus tachycardia when a sinus rate over 0OO a minute occurred in two or more records. Hospital mortali...

BACKGROUND Recent reports suggest that adenosine, in addition to terminating supraventricular tachycardia involving the atrioventricular (AV) node, may have antiarrhythmic effects on atrial tachycardia. The electrophysiological effects of adenosine on supraventricular tissue include shortening of action potential duration in atrial myocytes mediated by the potassium current, IKACh,Ado; shorteni...

BACKGROUND Heart rate (HR) variability reflects the neural regulation of normal pacemaker tissue, but the autonomic nervous regulation of abnormal atrial foci originating outside the sinus node has not been well characterized. We compared the HR variability of tachycardias originating from the ectopic foci and the sinus node. METHODS AND RESULTS R-R-interval variability was analyzed from 24-h...

We have developed a tachycardia detection scheme for use in an antitachycardia pacemaker in which the use of a properly timed atrial extrastimulus provides a means of discriminating sinus tachycardia from pace-terminable 1:1 tachycardias. An atrial extrastimulus is delivered in late diastole (80 ms premature), and the ventricular response is monitored. In sinus tachycardia, the ventricular resp...

We report a rare case of atrial tachycardia originating from the non-coronary aortic sinus. After failed radiofrequency (RF) energy applications at right His-bundle region, the complete elimination of atrial tachycardia was achieved with an RF energy application in the non-coronary aortic sinus. With the review of other papers, this report emphasizes the importance of mapping in the non-coronar...

We describe a case of 47-year-old man who suffered a sinus node reentrant tachycardia and a typical counterclockwise cavotricuspid isthmus dependent atrial flutter. The dynamic isopotential mapping with non-contact mapping system showed that source and propagation sequence of the sinus node reentrant tachycardia almost identical to that of sinus rhythm, only the foremost was slightly different....

myocardial infarction and tobacco smoking: risk of heart rhythm and conduction disorders e imani , msc n hajizadeh , bs z khademy , msc f naghizadeh , bsc received: 6 aug, 2009 accepted: 17 oct, 2009 abstract background & aims: smoking increases risk of myocardial infarction and its complications. in addition, it increases blood pressure, heart rate and vasoconstriction. the purpose of this res...

Patients with episodic sinus tachycardia and associated orthostatic intolerance present a diagnostic and management dilemma to the clinician. We define this group of disorders to include sinus node reentrant tachycardia (SNRT), inappropriate sinus tachycardia (IAST), and postural orthostatic tachycardia syndrome (POTS). After a brief review of the current understanding of the pathophysiology an...

A 42-year-old woman was referred for radiofrequency catheter ablation of narrow QRS tachycardia that was terminated with intravenous adenosine. Baseline twelve-lead ECG was normal during sinus rhythm and transthoracic echocardiography demonstrated no evidence of structural heart disease. The electrophysiological study showed a normal AH interval of 114 ms and HV interval of 37 ms during sinus r...