Normal Myocardial Enzymes and Normal Echocardiographic Findings During Noninvasive Transcutaneous Pacing

Abstract

Noninvasive transcutaneous pacing was performed for 30 minutes in 10 healthy volunteers. The pace rate was from 85 to 115 min-1, and the threshold for pacing was from 38 to 70 mA, median 59 mA. Echocardiography before and during pacing showed no changes in left ventricular end-diastolic diameter, in fractional shortening nor in contraction pattern. Also, blood pressure remained unchanged. Blood samples for determination of myoglobin, creatine phosphokinase, creatine kinase MB and lactate dehydrogenase were drawn prior to pacing and 1,2,3,4,6,8 and 24 hours after pacing. The serum concentrations were the same before and after pacing for all enzymes and myoglobin. We conclude that non-invasive transcutaneous pacing for 30 minutes causes no muscular or myocardial injury and that the left ventricular function remains normal.

Noninvasive Transthoracic Temporary Cardiac Pacing in Dogs

“…Moreover, neither ECG 23 nor clinically relevant histopathologic 23,24,27 evidence of myocardial injury was identified in any dog that was paced with the noninvasive transthoracic pacing system. Because of the safety and efficacy previously shown in both human studies 13,14,17,18 and animal studies, [23][24][25][26][27], the noninvasive cardiac pacing system is widely accepted in human emergency medicine, especially in bradyasystolic arrests and prehospital cardiac pacing settings. 20,22 Noninvasive cardiac pacing is preferred to transvenous pacing in life-threatening situations because of the shorter time to implementation.…”

“…In humans, the noninvasive transthoracic pacing success rates have ranged from 40 to 94% in several studies. 14,17,20,22 Failure to pace with the noninvasive pacing system usually results from suboptimal electrode placement, obesity, air trapping, pneumothorax, large pericardial or pleural effusions, or intolerable pain in patients with high current requirements. We were able to successfully pace 100% of the dogs in which the noninvasive transthoracic pacing was attempted.…”

“…11 After some modifications of the original design, these noninvasive external transthoracic pacing systems have been used for the acute care of humans for nearly 20 years. [12][13][14][15][16][17][18][19][20][21][22] Transthoracic pacing is desirable because it is a safe, easy, and noninvasive system for temporary cardiac pacing. After performing an initial study on 2 normal dogs to determine optimal transthoracic electrode placement, we report the safety and efficacy of a noninvasive transthoracic temporary pacing system in a series of dogs with clinically relevant bradyarrhythmias pre-sented to the Veterinary Teaching Hospital at North Carolina State University (Raleigh, NC) from 1995 to 2000.…”

Evaluation of changes in cardiac biomarker concentrations and enzyme activities in serum after short- and long-duration transcutaneous cardiac pacing in dogs

“…1 The safety of prolonged use of TCP has always been a concern. However, in several studies [2][3][4][5] in dogs and humans, no enzymatic, ECG, or microscopic evidence of myocardial damage after pacing for as long as 30 minutes has been detected. In addition, in dogs with experimentally induced anoxia, TCP stimulation Evaluation of changes in cardiac biomarker concentrations and enzyme activities in serum after short-and long-duration transcutaneous cardiac pacing in dogs Procedures-In each dog, anesthesia was induced with propofol (5 mg/kg, IV) and maintained via inhalation of isoflurane in oxygen.…”

“…6 Only 1 of the 32 human patients who received TCP in another study 7 developed ventricular fibrillation; however, lifethreatening ventricular arrhythmias were induced in dogs in which the capture energy used was 10 times as great as the pacing threshold. 8 Despite the fact that application of TCP for a period of 30 minutes appears not to induce serious myocardial injuries in dogs and humans, 2,3,5 the safety assessment of TCP of longer duration (ie, periods > 1 hour) may be more appropriate because most patients generally require treatment with TCP for long periods in clinical situations. However, the long-term use of TCP in either humans or dogs has never been investigated to our knowledge.…”