Search results for "Atrioventricular node"
showing 2 items of 12 documents
Intrinsic changes on automatism, conduction, and refractoriness by exercise in isolated rabbit heart.
2001
We have studied the intrinsic modifications on myocardial automatism, conduction, and refractoriness produced by chronic exercise. Experiments were performed on isolated rabbit hearts. Trained animals were submitted to exercise on a treadmill. The parameters investigated were 1) R-R interval, noncorrected and corrected sinus node recovery time (SNRT) as automatism index; 2) sinoatrial conduction time; 3) Wenckebach cycle length (WCL) and retrograde WCL, as atrioventricular (A-V) and ventriculoatrial conduction index; and 4) effective and functional refractory periods of left ventricle, A-V node, and ventriculoatrial retrograde conduction system. Measurements were also performed on coronary…
A particular bigeminy during atrial tachycardia.
2014
The ECG shows clearly visible P waves only in lead V1 (Fig. 1). Regular PP intervals and an isoelectric baseline are present between the P waves, so the diagnosis is atrial tachycardia [1]. During the ECG recording, lead V1 shows 12 P waves but some of these are not visible because they are concealed by the QRS complex (Fig. 2). In lead V1, the beats following the long RR intervals are conducted by the first and the seventh P wave and the premature QRS complexes are conducted by the third and the ninth P wave because the fourth and the tenth P wave are too close to the following QRS complex to conduct the impulse. Consequently, the atrial tachycardia presents an alternating 2:1 and 4:1 cond…