New directions in cardiovascular mapping and therapy.
Cardiovascular mapping has allowed us to fully understand the mechanisms of some of the cardiac arrhythmias and enabled us to devise new therapeutic options for them. Endocardial mapping by electrophysiological studies using three to four endocardial catheters introduced via the vein or artery to the heart allows us to directly map the electrical activity of the heart during sinus rhythm and during abnormal tachyarrhythmias. The simultaneous recording of electrical activity from the surface electrocardiogram, right ventricular apex, His bundle, high right atrium, coronary sinus, with or without a roving mapping catheter, enables us to precisely map the electrical activation sequence in the heart. This technique has been especially useful for mapping supraventricular tachycardias and the precise mapping of the accessory pathway or slow pathway potentials have now allowed us to selectively ablate them using radiofrequency energy delivered via the tip of the endocardial catheter. Intraoperative direct cardiac mapping has allowed us to reconfirm the findings of endocardial catheter mapping immediately prior to surgery. The intraoperative mapping is more precise and allows direct visualisation of the abnormal site for the surgeon to operate. Computerised mapping using multichannel recordings has facilitated mapping of the abnormal site for patients with haemodynamically unstable or nonsustained ventricular tachycardia, and thus allows the surgeon to perform surgical resection or cryoablation of the abnormal site. Cardiovascular mapping has thus enabled us not only to understand the mechanisms of cardiac arrhythmias but allows us to provide curative therapy for patients who are at risk from sudden arrhythmic death or otherwise need life long drug therapy.
Teo
W S
WS
Department of Cardiology, Singapore General Hospital.
Tan
A
A
Ng
A
A
Wong
J
J
D000328:Adult; D001145:Arrhythmias, Cardiac / Q000150:complications / Q000175:diagnosis* / Q000601:surgery*; D017115:Catheter Ablation / Q000295:instrumentation / Q000379:methods* / Q000639:trends; D003452:Cryosurgery / Q000379:methods; D016757:Death, Sudden, Cardiac / Q000453:epidemiology / Q000209:etiology; D003936:Diagnosis, Computer-Assisted / Q000379:methods*; D004562:Electrocardiography / Q000295:instrumentation / Q000379:methods; D004568:Electrodiagnosis / Q000295:instrumentation / Q000379:methods* / Q000639:trends; D004594:Electrophysiology / Q000295:instrumentation / Q000379:methods / Q000639:trends; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000295:instrumentation / Q000379:methods / Q000639:trends; D012307:Risk Factors