| ventricular demand triggered p. |
an artificial cardiac pacemaker that delivers stimuli to the ventricle at a fixed rate in the absence of sensed ventricular activity; spontaneous cardiac activity triggers pacemaker output, which falls ineffectively in the myocardial refractory period and initiates a new cycle of pacemaker stimulation. Called also VVT p.
Ãâó: www.mercksource.com/pp/us/cns/cns_health_library.j...
|
|---|---|
| ventricular e. |
the occurrence of one or more ectopic beats in which a ventricular pacemaker becomes effective before the sinoatrial pacemaker; it usually occurs with slow sinus rates and often, but not necessarily, with increased vagal tone. See also under beat and rhythm.
Ãâó: www.mercksource.com/pp/us/cns/cns_health_library.j...
|
| ventricular escape b. |
an ectopic beat of ventricular origin occurring in the absence of supraventricular impulse generation or conduction; it is characterized by a bizarre, usually wide QRS complex and lack of an ectopic P wave.
Ãâó: www.mercksource.com/pp/us/cns/cns_health_library.j...
|
| ventricular f. |
arrhythmia characterized by fibrillary contractions of the ventricular muscle due to rapid repetitive excitation of myocardial fibers without coordinated contraction of the ventricle; it is an expression of randomized circus movement or of an ectopic focus with a very rapid cycle. Abbreviated VF or VFib. Click here to view image■Ventricular fibrillation, characterized by irregular undulations without clear ventricular complexes.
Ãâó: www.mercksource.com/pp/us/cns/cns_health_library.j...
|
| ventricular filling p. |
see under period.
Ãâó: www.mercksource.com/pp/us/cns/cns_health_library.j...
|