Use of temporary atrial pacing in management of patients after cardiac surgery

The authors' clinical experience with temporary atrial pacing to evaluate its use in the management of patients after cardiac surgery was reviewed. A total of 339 patients undergoing cardiac surgery were studied with regard to postoperative pacing therapy. Postoperative pacing was performed in 186 of 339 patients to treat supraventricular bradycardia or tachyarrhythmias. Rapid atrial pacing was performed to interrupt re-entrant supraventricular tachyarrhythmias. In bradycardic patients, haemodynamics could be improved as the result of significant increase of blood pressure and oxygen saturation in the pulmonary artery (Svo₂) caused by atrial pacing. Premature beats could be suppressed in 63% and supraventricular tachyarrhythmias could be interrupted in 66% of the patients only by atrial pacing. Temporary atrial pacing is safe, rapid and effective as the treatment of choice; it is believed that the technique should be applied in preference to pharmacological treatment in the management of patients after cardiac surgery. Copyright © 1996 The International Society for Cardiovascular Surgery.     

Improved silastic sleeve temporary cardiac pacing electrodes

New atrial clip-on and ventricular suture-on temporary pacemaker electrode systems were evaluated in dogs. The ability of these electrodes to sense cardiac electrical activity was evaluated during a 14-day period. At no time did the P-wave potential fall below 3.3 mV and the R-wave potential fall below 6.0 mV. The acute pacing thresholds never exceeded 1.025 V and 1.95 mA. All values are well within acceptable standards for temporary pacing. The lead wires were easily, quickly, and painlessly removed without injury to the myocardium, yet the electrical contact remained tight between the lead wire and electrode preventing premature displacement.     

Indications for and complications of temporary transvenous cardiac pacing

A prospective survey was conducted of the indications for and complications of 153 temporary transvenous cardiac pacing lead insertions in 148 patients. Pacing for bradyarrhythmias or potential bradyarrhythmias (Group I) accounted for 105 insertions, wide complex tachycardia (Group II) 17, and narrow complex tachycardia (Group III) 31 pacing electrode insertions respectively. The infraclavicular subclavian vein approach was used in 73%. The median insertion time was 20 minutes. Group I: 77% were undertaken because of severe symptoms. On 64 occasions (61%) the patient had complete heart block or ventricular asystole. Group II: The lead was inserted to treat and often assist in the diagnosis of the wide complex tachycardia. Ventricular 'burst' pacing reverted ventricular tachycardia in 13 (76%). Group III: Rapid atrial 'burst' pacing was used to treat supraventricular tachyarrhythmias (paroxysmal supraventricular tachycardia and atrial flutter) resistant to medical therapy. Pacing was successful in reverting 28 (90%). A complication occurred in 27 (18%) of 153 lead insertions, 11 (7%) were serious. No complication resulted in the death of a patient. Temporary transvenous pacing is safe and effective for the treatment of bradyarrhythmias and certain tachyarrhythmias.     

Optimal positioning of temporary epicardial atrial pacing leads after cardiac surgery

OBJECTIVES: Atrial pacing plays an important role in preventing low output syndrome and arrhythmia after cardiac surgery. We studied the optimal positioning for temporary epicardiac atrial pacing. METHODS: The performance of temporary epicardiac atrial pacing leads was examined after 13 cases of elective coronary artery bypass grafting between October 1999 and January 2000. Two bipolar electrode leads were used--1 on the cephalic atrial wall between the left and right atrial appendages, where the Bachmann bundle indwells (site A), and the other on the interatrial groove (site B). To assess pacing performance on postoperative days 1, 2, and 7, we measured 3 pacing patterns--bipolar use of sites A and B leads, and combined use of the 2 with the site A lead acting as the negative electrode and the site B lead as the ground. The pacing threshold was measured at a 0.5 ms pulse width, using the P wave amplitude and slew rate as indicators of sensing performance. RESULTS: Bipolar pacing both at sites A and A-B was superior to that at site B in pacing threshold and sensing parameters. CONCLUSIONS: The negative electrode at site A is mandatory for high atrial pacing and sensing performance.     

A critical look at temporary ventricular pacing following cardiac surgery.

The effect of atrial, ventricular, and atrioventricular (A-V) sequential pacing on cardiac output (CO) was evaluated in patients within 24 hours after cardiac surgery. In patients with normal sinus rhythm, ventricular pacing reduced CO by as much as 42% (average, 14%), whereas atrial and A-V sequential pacing at the same rate increased CO by averages of 13% and 19%, respectively. In patients with junctional rhythm, increase of the heart rate by ventricular pacing produced an increase in CO, however, and an additional 25% increase in CO could be obtained by atrial or A-V sequential pacing at the same rate. Atrial or A-V sequential pacing was superior to ventricular pacing at the same rate and they are the preferred methods for temporary carciac pacing in the postoperative period. In suitable cases elective A-V sequential pacing is an effective method for increasing CO after cardiac surgery.     

Anaesthetic management of severe bradycardia during general anaesthesia using temporary cardiac pacing

There are few reports of management of severe bradycardia withtemporary cardiac pacing. We describe a 65-yr-old female patientwho developed bradycardia and hypotension on two occasions duringgeneral anaesthesia for laryngoscopy. The first episode wastreated with atropine, ephedrine, and colloid infusion and thesecond with a temporary pacemaker and ephedrine. Br J Anaesth 2002; 89: 655–7     

Optimal position of atrial epicardial leads for temporary pacing in infants after cardiac surgery

Background. The atrial epicardial wall of pediatric patients was topographically assessed to identify the optimal position for temporary atrial pacing.

Methods. Unipolar electrodes were fixed at the cephalic wall between the right and left atrial appendages, the interatrial groove, and the right atrial appendage of fifteen pediatric patients who underwent definitive surgical repair. The performance of the three electrodes in terms of pacing patterns and six combinations of bipolar pacing were evaluated in terms of the pacing threshold, P-wave amplitude, slew rate, and lead impedance.

Results. Unipolar pacing of the right atrial appendage showed a significantly higher threshold than the other groups. A bipolar configuration of the cephalic atrial wall and interatrial groove had a significantly higher P-wave amplitude than groups without the electrode at the cephalic atrial wall, and a significantly higher slew rate than a unipolar configuration of the atrial appendage.

Conclusions. Bipolar pacing with the negative electrode at the cephalic atrial wall and the indifferent electrode at the interatrial groove is the most efficient method for pediatric patients.     

Permanent cardiac pacing in patients on chronic dialysis

Four patients on chronic dialysis, who underwent permanent pacemaker implantation, were reviewed. The indication for pacing was sick sinus syndrome in three patients and complete atrioventricular block in one. Physiological pacing modes were chosen in all patients (DDD in three and AAI in one). Sensing and pacing properties in these patients studied at implantation and at follow-up (22-41 months after implantation) were similar as those in non-dialysis patients. However, the study of these properties during hemodialysis showed a significant elevation of atrial pacing threshold associated with marked decrease of serum potassium concentration in two patients. We conclude that dialysis patients with significant bradyarrhythmia should be considered for pacemaker implantation in the same manner as non-dialysis patients. However, special attention should be payed on the elevation of pacing threshold during hemodialysis.     

Efficacy of noninvasive transcutaneous cardiac pacing patients undergoing cardiac surgery

Noninvasive transcutaneous cardiac pacing (NTP) is a rapid, safe, and easily utilized form of emergency cardiac pacing, with hemodynamics similar to right ventricular endocardial pacing. Although the technique has proven effective for hemodynamically significant bradycardias and early use during cardiopulmonary resuscitation, NTP under anesthetic conditions has been poorly characterized. In particular, it is unknown to what degree the multiple physiologic perturbations of cardiac surgery and cardiopulmonary bypass (CPB) affect myocardial thresholds and the efficacy of the unit itself. Patients undergoing procedures utilizing CPB (n = 23) were studied in an effort to address these issues. All patients were able to be paced at all points throughout the 24-h study interval, although four patients developed hemodynamic instability during this period causing their exclusion from additional investigation. Only one patient requested discontinuation from the study due to discomfort. A statistically significant increase in mean current requirements for capture was demonstrated over time (P less than 0.0001), with baseline thresholds being significantly less than other study points (P less than or equal to 0.05). Thresholds following chest wall closure were significantly greater than all other study points (P less than or equal to 0.05), possibly due to accumulation of pericardial and mediastinal air. Multiple measured variables changed significantly during the study, but only increases in cardiac output and core temperature were related to statistically significant increases in current thresholds (P less than or equal to 0.05). Increasing age and pump time were of borderline importance. NTP represents an effective pacing alternative in cardiac surgical patients.     

Unconventional approaches to cardiac pacing in patients with inaccessible cardiac chambers.

BACKGROUND: Transvenous endocardial implantation can be impossible or contraindicated in patients with inaccessible right cardiac chambers. These patients usually undergo epicardial implantation, which has been associated with frequent rising thresholds and limited lead survival. We have used the following two alternative approaches in these patients: (1) transatrial puncture and passage of pacing leads for patients with no access to the right atrium and (2) ventricular pacing from the coronary sinus or its tributaries for patients with inaccessible ventricles. METHODS. We retrospectively reviewed our experience in 9 patients who had those procedures. Five patients had pacing from the coronary sinus, and 4 by transatrial puncture. RESULTS: Seven of the 9 patients had DDD pacing. Low acute pacing thresholds and satisfactory sensing levels were obtained with both approaches. One instance of high stimulation threshold (20%) occurred in the coronary sinus group and none in the transatrial puncture group. One patient in the transatrial puncture group died from unrelated causes. No malignant arrhythmias, pneumothorax, diaphragmatic pacing, or infectious complications have been observed. CONCLUSION: These unconventional approaches are safe, relatively simple, and reliable. Although the short-term follow-up is favorable, long-term follow-up is necessary to ascertain the relative merit of these approaches.     

Colonic injury from temporary epicardial pacing wires

A 72-year-old man who had undergone a three-vessel coronary artery bypass grafting, aortic valve replacement, and tricuspid valve repair became comatose 1 week after the procedure. Signs of intraabdominal sepsis developed 6 days later, leading to laparotomy on his 12th postoperative day. The Intraoperative finding was a perforating injury to the transverse colon caused by the ventricular temporary pacing wires. A defunctioning double-barreled transverse colostomy was performed, after which the patient started to recover. He was discharged home 2 weeks later.