Filter by keywords:



Filtering documents. Please wait...

1/6. Intermittent ventricular bigeminy as an expression of two-level Wenckebach periodicity in the reentrant pathway of extrasystoles.

    A patient with intermittent ventricular bigeminy is reported in whom the presence of two-level Wenckebach periodicity in the reentrant pathway of extra-systoles is suggested. When sinus arrest was caused by vagal stimulation, no ectopic QRS complex occurred. This indicated that ventricular bigeminy was not parasystolic bigeminy but ordinary extrasystolic bigeminy. Observations of the electrocardiogram suggested that Wenckebach block occurred at two different levels in the reentrant pathway of ventricular extrasystoles. When extrasystoles were noninterpolated, Wenckebach block occurred at the distal level of the pathway and caused termination of ventricular bigeminy. On the other hand, when extrasystoles were interpolated, Wenckebach block occurred at the proximal level of the pathway. This is the first report to suggest the presence of two-level Wenckebach periodicity in a reentrant pathway of extrasystoles.
- - - - - - - - - -
ranking = 1
keywords = periodicity
(Clic here for more details about this article)

2/6. Periodic changes in cycle length of ventricular tachycardia: a Wenckebach type exit block?

    A 55-year-old female developed ventricular tachycardia (VT) which showed a Wenckebach periodicity in cycle length. She had had a myocardial infarction about ten years previous and, at age 51, felt fatigability and palpitations. The ECG showed VT. Thereafter, she had had palpitations of short duration two to three times a year. On the last admission she developed fatigability; the ECG showed VT. lidocaine (100 mg i.v.) did not terminate VT. procainamide (600 mg) could not terminate the VT, but the rate became slower. Programmed stimulation was given at bedside which effectively terminated VT. Electrophysiologic study induced VT in a reproducible manner. Ventricular tachycardia showed initial fluctuation in cycle length which stabilized at 270 msec. disopyramide therapy (400 mg/day p.o.) was begun and electrophysiologic study was repeated one week later. VT was again induced but the cycle length was a little longer. A periodic change in cycle length from 328 to 442 msec was repeated. The change in cycle length was uniformly found in surface leads (I, II, V1) and intracardiac electrograms from the right ventricular apex and the His bundle region. No change in QRS complex was found and the periodicity was unrelated to atrial activity. A Wenckebach type exit block was therefore suggested; disopyramide might be responsible for the development of the block. We could not find another such case in the literature.
- - - - - - - - - -
ranking = 0.33333333333333
keywords = periodicity
(Clic here for more details about this article)

3/6. Type A alternating Wenckebach periodicity in the reentrant pathway of interpolated ventricular extrasystoles.

    A 67-year-old man with interpolated ventricular extrasystoles is reported in whom alternate sinus QRS complexes were followed by interpolated ventricular extrasystoles with progressively lengthening coupling intervals until one of these alternate sinus complexes failed to be followed by an extrasystole. This is the first report to suggest the presence of type A alternating Wenckebach periodicity in the reentrant pathway of interpolated ventricular extrasystoles. It is suggested that 2:1 block occurred at a proximal level in the reentrant pathway, while Wenckebach block occurred at a distal level in the pathway.
- - - - - - - - - -
ranking = 0.83333333333333
keywords = periodicity
(Clic here for more details about this article)

4/6. Permanent form of junctional reciprocating tachycardia with only even-numbered beats.

    An analysis of the electrocardiogram of a patient with the permanent form of junctional reciprocating tachycardia is presented. The patient demonstrated near-incessant tachycardia, with a 1:1 atrioventricular relationship and a retrograde P wave (P') occurring closer to the succeeding QRS complexes (ie, with a P'R interval that is shorter than the RP' interval). Each tachycardia episode was characterized by alternating short and long cardiac cycles due to alternation of retrograde conduction time (RP' interval), retrograde Wenckebach periodicity, and an even number of ectopic P' waves. The authors propose that there is an accessory AV connection with decremental functional properties that arborizes into two atrial branches with different conduction times. The fast branch initially exhibits a 3:2 retrograde conduction block followed by a cycle length-dependent 2:1 retrograde conduction block, thereby permitting alternate use of the slow branch, which is the weakest component of the reciprocating process.
- - - - - - - - - -
ranking = 0.16666666666667
keywords = periodicity
(Clic here for more details about this article)

5/6. Type A alternating Wenckebach periodicity in the re-entrant path of ventricular extrasystoles.

    A patient with ventricular extrasystoles is reported in whom Type A alternating Wenckebach periodicity in the re-entrant path of the extrasystoles is suggested for the first time. Namely, it appears that 2:1 exit block occurs at a proximal level in the re-entrant path and block of the Wenckebach form occurs at a distal level in the path. The presence of three-level block in the re-entrant path is also suggested in this patient.
- - - - - - - - - -
ranking = 0.83333333333333
keywords = periodicity
(Clic here for more details about this article)

6/6. Mechanism of bradycardia-dependent appearance of manifest extrasystoles in concealed ventricular trigeminy.

    A man with ventricular extrasystoles is described. To our knowledge, this is the first report of bradycardia dependent appearance of manifest extrasystoles in concealed trigeminy. The mechanism was satisfactorily explained, using the concepts of longitudinal dissociation and concealed 3:2 Wenckebach periodicity in the reentrant pathway of extrasystoles.
- - - - - - - - - -
ranking = 0.16666666666667
keywords = periodicity
(Clic here for more details about this article)


Leave a message about 'Cardiac Complexes, Premature'


We do not evaluate or guarantee the accuracy of any content in this site. Click here for the full disclaimer.