Methods are provided for conducting diagnostic or therapeutic medical or
surgical procedures in a patient wherein, during the procedure, autonomous
ventricular electrical conductivity and escape beats are reversibly and
transiently suppressed to facilitate the procedure. Also provided are
compositions which are capable of inducing ventricular asystole in a
patient. The compositions may include an atrioventricular (AV) node
blocker. In one embodiment, compositions including an AV node blocker and
a .beta.-blocker are provided, wherein the .beta.-blocker is present in an
amount sufficient to substantially reduce the amount of AV node blocker
required to induce ventricular asystole in the patient. The compositions
and methods may be used for inducing temporary ventricular asystole in a
beating heart, and to facilitate the performance of a variety of
techniques, including minimally invasive microsurgical techniques. Methods
for performing a diagnostic or therapeutic procedure on a human patient
are provided wherein a composition capable of inducing transient
reversible ventricular asystole is administered to the heart, for example
by intracoronary injection. In one embodiment, the heart then is
electrically paced using an electrical pacing system, thereby to maintain
the patient's blood circulation. The electrical pacing then is selectively
intermittently stopped to allow ventricular asystole to occur, and the
steps of the diagnostic or therapeutic procedure, such as suturing, are
conducted during the time that the electrical pacing is intermittently
stopped. In one embodiment, pacing is not required, and at least one step
of a procedure is conducted during a period of ventricular asystole. The
methods and compositions advantageously may be used in a range of
different diagnostic or therapeutic procedures including imaging
procedures, placement of stents, grafts, and embolic devices, and cardiac,
vascular and neurosurgical procedures.
