Temporary use of an eroded bipolar pacemaker system

Over a 2.5-year period, of 176 bipolar pacemaker procedures, six were complicated by erosion (incidence, 3.4%). One patient was treated whose pacemaker was inserted at another hospital. Time from insertion to presentation ranged from 5 to 23 months. When infection was present, Staphylococcus epidermidis was found to be the offending organism. We have used a staged method for managing this problem. Initially, the bipolar pulse generator was exteriorized and worn suspended around the neck while infection was controlled. A new pacemaker system (catheter and pulse generator) was inserted from the opposite side once infection was controlled. The main advantage of this type of approach is that the old pacing catheter and old bipolar generator can be used as an effective temporary pacing system, while the infection is being controlled thus eliminating the step of inserting a temporary pacing catheter after the eroded generator and catheter have been removed. A temporary pacing catheter is only safe and effective for a few days (perhaps up to a week), and this may not be sufficient time to be sure that infection is locally controlled. In addition, the patient can be ambulatory as the old permanent catheter is not likely to be dislodged easily as compared with a temporary catheter. Follow up ranging from 2 to 23 months has shown this to be an effective method for treating bipolar pacemaker erosion or infection in all instances without further infection or complication.     

Anesthesic management of thoracic aortic stent graft deployment using rapid ventricular pacing

Controlled hypotension is useful for accurate deployment of an aortic endograft. We describe the use of rapid ventricular pacing during thoracic aortic stent graft deployment. Anesthesia was induced and maintained with intravenous propofol and remifentanil. A pulmonary artery catheter with pacing function was introduced, and rapid ventricular pacing was started before stent graft deployment. Pacing mode was VVI and pacing rate was 120-160 beats min(-1). Aortic pressure and flow decreased immediately and were maintained at low levels during surgical manipulation. After stopping rapid ventricular pacing, heart rate and aortic pressure recovered immediately. Rapid ventricular pacing was performed 4 times, and there were no complications such as entailed arrhythmia. With rapid ventricular pacing maneuver, which is thought to cause a rapid change in cardiac output, continuous cardiac output measurement can be a useful monitor. This procedure has advantages over pharmacologic or other methods of aortic pressure reduction. Rapid ventricular pacing is safe and effective during stent graft positioning and deployment.     

Temporary left ventricular pacing improves haemodynamic performance in patients requiring epicardial pacing post cardiac surgery.

OBJECTIVE: In the 1990s, sequential atrio-ventricular pacing demonstrated haemodynamic benefit relative to right ventricular pacing in patients with sinus rhythm requiring pacing post cardiopulmonary bypass. The benefit of biventricular pacing has been demonstrated in non-surgical patients with severe left ventricular dysfunction. It was hypothesised that left ventricular pacing would increase cardiac output in surgical patients. We report the findings of a prospective trial of left ventricular pacing with active lead placement on the anterior or posterior left ventricular surface, compared to standard practice of active lead placement on the right ventricular surface. METHODS: Twenty five patients with left ventricular dysfunction underwent pacing with active lead placement on the right ventricle (control), the anterior left ventricle and the posterior left ventricle in random order, with each pacing mode of 10 min duration, following cardiopulmonary bypass. Haemodynamic parameters were measured with a thermodilution pulmonary artery catheter. Patients provided their control values. RESULTS: In the 25 patients studied, pacing with the active lead posteriorly on the left ventricle increased cardiac index from 2.74 to 3.08 l/min per m2 (P=0.019). Significant increases in mean arterial pressure with the use of this pacing mode were observed. There were no complications relating to application or removal of the left ventricle pacing leads. CONCLUSIONS: Left ventricular pacing with active lead placed on the postero-lateral left ventricular wall affords haemodynamic benefit to cardiac surgical patients.     

Simplified physiological pacing after cardiac surgery

Temporary pacing wires are routinely placed at the end of cardiac surgery. These pacing wires are helpful in maintaining patients with postoperative bradycardias, and physiological pacing is also more desirable in critically ill patients. We herein report our simplified procedure for atrial pacing. This technique uses commercially available intravenous pacing catheters. The catheter is passed through the skin, and its tip is placed at the pericardial oblique sinus just between the right and left pulmonary veins. Atrial pacing is then initiated with a temporary pulse generator. This procedure is simple and effective for patients undergoing cardiac surgery. We also report two clinical cases that satisfactorily underwent atrial pacing using this procedure.     

Temporary transmyocardial pacing using epicardial pacing wires and pacing pulmonary artery catheters

This study investigated the feasibility of transmyocardially pacing the heart using one temporary epicardial pacing lead and one endocardial lead of a pacing pulmonary artery catheter. Twenty patients undergoing cardiopulmonary bypass with cardioplegic arrest were studied 10 to 45 minutes and 18 to 30 hours after discontinuation of cardiopulmonary bypass. The Swan-Ganz Flow-Directed Pacing TD Catheter (Baxter Healthcare Corporation) was inserted in one group of 10 patients, and the Swan-Ganz Thermodilution A-V Paceport Catheter (Baxter Healthcare Corporation, Irvine, CA) was used in another group of 10 patients. Using the Pacing TD Catheter, transmyocardial atrial (TMA) pacing was successful in 14 of 16 attempts (87.5%), and transmyocardial ventricular (TMV) pacing was successful in 15 of 16 attempts (93.8%). With the AV Paceport Catheter, TMA pacing was successful in 16 of 18 attempts (88.9%), and TMV pacing was successful in 17 of 19 attempts (89.5%). Transmyocardial atrial-ventricular sequential pacing was achieved in all cases when both TMA and TMV pacing were independently successful. There were no significant differences between catheters in the success rates of either TMA or TMV. It is concluded that transmyocardial pacing is feasible using one temporary epicardial pacing lead and one endocardial lead of a pacing pulmonary artery catheter.     

Epicardial atrial pacing using an active fixation bipolar endocardial lead in children

Good performance was observed over 10 years after implantation of bipolar epicardial atrial pacing using an active fixation bipolar endocardial lead in 3 pediatric patients with congenital heart block. The bipolar endocardial lead which was supposed to be fixed transvenously was implanted on the atrial surface by first screwing the lead's helix into the myocardium. The catheter was then laid down on the atrial surface, and both electrodes were wrapped by the atrial tissue. The good performance of this pacing lead seemed to depend on stable positioning of the electrode. This lead is superior to the commercially available, and steroid eluting epicardial bipolar pacing lead, on the point of its small size in head and body, and could be applied to dual chamber pacing in smaller children.     

Rapid Pacing Technique For Preventing Ventricular Tears during Transapical Aortic Valve Replacement

Abstract   Background: Transapical aortic valve replacement (TAVR) is emerging as an alternative to surgical aortic valve replacement in high-risk or non-operable patients with aortic stenosis. However, this approach might be associated with major bleeding complications during the removal of the introducer sheath from the left ventricular apex. We describe a simple technique to minimize this complication. Methods: The technique consists of installing a temporary pacing Swan-Ganz catheter, using large-needle Ethibond 2–0 sutures with large pledgets for apical pursestrings, and removing the 26F sheath from the ventricular apex tension-free by rapid ventricular pacing (>150 bpm). Results: We have completed 21 TAVR using rapid ventricular pacing. This technique considerably decreased the amount of apical tearing and sutures to be added at the apex. Six of 21 patients had partial ventricular tearing that was amenable to repair using rapid pacing, thereby avoiding urgent cardiopulmonary bypass. Conclusion: The present report describes a technique to reduce the occurrence of ventricular tears and major bleeding during TAVR.     

Transvenous Insertion of Double Sets of Permanent Electrodes Through a Single Introducer: Clinical Application

Described is a simplified method for the insertion of separate atrial and ventricular permanent pacing electrodes. A single subclavian catheter may be used to pass both electrodes, thus facilitating the procedure.     

Effect of pacemaker-induced arrhythmias on coronary blood velocity in conscious man.

With the use of the Doppler ultrasonic catheter telemetry system, phasic left coronary blood velocity was measured in 34 conscious subjects during transvenous pacemaker insertion and right ventricular endocardial pacing. Ventricular premature depolarizations and ventricular tachycardia, occurring as consequences of pacing catheter manipulation and competitive rhythms, reduced peak coronary blood velocity by approximately one halft. These findings provide insight into the genesis of sudden death associated with pacemaker insertion, competitive or repetitive arrhythmias, and pacemaker "runaway."     

Anesthetic management of a patient undergoing liver transplantation who had previous coronary artery bypass grafting using an in situ right gastroepiploic artery

We describe successful anesthetic management during living-donor liver transplantation in a 63-year-old man with previous coronary artery bypass grafting (CABG) that employed an in situ right gastroepiploic artery (RGEA). Anesthesia was maintained with 1.5% isoflurane in air/oxygen and fentanyl. A five-lead electrocardiogram, transesophageal echocardiogram, and pacing pulmonary artery catheter evaluated cardiac function. A pacing wire was inserted through the catheter to prepare for intraoperative severe bradyarrhythmia. Olprinone and nicorandil were continuously infused to prevent decrease in coronary arterial blood flow and the collapse of cardiac function. Avoiding disruption of circulation to coronary arteries through injury or spasm of the RGEA graft and preparing for cardiac insufficiency during liver transplantation of a patient with previous CABG using an in situ RGEA is critical.     

The effect of pericardial restraint,atrial pacing,and increased heart rate on left ventricular systolic and diastolic function in patients undergoing cardiac surgery

Baseline measurements of systolic and diastolic function performed after the induction of anesthesia may be compared with subsequent measurements acquired under different physical conditions such as open pericardium and different heart rate or rhythm. We acquired data from 21 patients undergoing coronary artery surgery. Combined echocardiographic and pulmonary artery catheter measurements were performed before and after pericardial opening, atrial pacing at the native rate, and atrial pacing 30 bpm faster. Indices of systolic function included fractional area change, afterload corrected fractional area change, and myocardial performance index; diastolic function included mitral inflow and pulmonary vein Doppler profiles, color M-Mode Doppler flow propagation velocity, instantaneous end-diastolic stiffness, and isovolumetric relaxation time. Hemodynamic indices included cardiac index, mean arterial, right atrial, and pulmonary capillary wedge pressures, and systemic vascular resistance index. There were no changes in measurements after opening of the pericardium or with institution of atrial pacing. With increased heart rate, there were no changes in systolic function, but instantaneous end-diastolic stiffness increased. Propagation velocity showed a paradoxical improvement with increased heart rate opposite to other trends. Beat fusion occurs with increasing heart rate for mitral inflow Doppler. We recommend that serial measurements are performed at a similar heart rate. IMPLICATIONS: Pericardial restraint or the institution of atrial pacing do not alter left ventricular function, as assessed by pulmonary artery catheter and transesophageal echocardiography measurements. Diastolic (but not systolic) measurements showed inconsistency with increased heart rate.     

Indications for the use of pacing pulmonary artery catheters in cardiac surgery.

Several varieties of pulmonary artery catheters (PACs) with pacing capabilities are now available. Although specific recommendations for prophylactic perioperative placement of pacemakers have been offered previously, the authors believe that those recommendations warrant further examination, taking into consideration the availability of new pacing modalities. Toward this end, the use of pacing PACs in cardiac surgical patients was prospectively examined. In 600 consecutive adult patients with PACs placed prior to cardiopulmonary bypass (CPB), the cardiac anesthesiologist recorded if a pacing PAC was placed, the indications for placing it, and whether the catheter was used to pace. If a pacing PAC was not chosen, the anesthesiologist indicated whether cardiac pacing was needed prior to CPB. In all patients, the presence and specifics of the following five possible indications were documented: sinus node dysfunction/bradydysrhythmias, atrioventricular heart block, fascicular or bundle branch block, cardiac reoperation, and/or valvular heart disease. PACs with pacing capability were placed in 180 of the 600 patients (30.0%) and were used in 34 of these 180 patients (18.8%). In 4 of 420 patients (0.95%) without pacing PACs, cardiac pacing was needed prior to CPB. The following preoperative diagnoses were significant predictors (P less than .05) for the use or need for pacing catheters: sinus node dysfunction/bradydysrhythmias, a history of transient complete atrioventricular block, aortic stenosis, aortic insufficiency, and reoperation. The majority of adult patients undergoing cardiac surgery do not require the use of a pacing PAC prior to CPB.(ABSTRACT TRUNCATED AT 250 WORDS)     

Management of phrenic nerve stimulation caused by epicardial pacemaker leads in children

To find a suitable site with good sensing and low pacing thresholds, it may be necessary to place an epicardial pacemaker lead in close proximity to the phrenic nerve. To prevent phrenic stimulation, a silastic patch can be sewn over the area of the pacing electrode to shield it from the nerve. This simple technique prevents diaphragm contraction and has not interfered with long-term pacemaker lead function.     

Electroanatomic mapping of transseptal conduction during coronary sinus pacing in patients with paroxysmal atrial fibrillation

OBJECTIVE: To delineate the electrophysiological properties of transseptal conduction from the left to the right atrium in patients with paroxysmal atrial fibrillation (AF). DESIGN AND RESULTS: Right atrial mapping using the electroanatomic mapping technique was performed at 111 +/- 16 sites in 16 patients with paroxysmal AF during pacing from distal coronary sinus (CS). A single transseptal breakthrough near the CS ostium was observed in all patients. The activation time from the pacing site to the earliest septal activation site was 47 +/- 13 ms. The total septal activation time (68 +/- 16 ms) was markedly longer but the total right atrial activation time (118 +/- 17 ms) was similar to that in patients without AF in a previous observation. CONCLUSION: During distal CS pacing, a preferential site of transseptal conduction near the CS ostium was demonstrated in patients with paroxysmal AF. This has clinical implications when surgical dissection or catheter ablation is considered to eliminate interatrial connection in patients with AF.     

The optimal oesophageal pacing technique--the importance of body position, interelectrode spacing, electrode surface area, pacing waveform and intra-oesophageal local anaesthesia

In order to improve the technique of transoesophageal atrial stimulation (TAS), the effects of body position, interelectrode spacing and electrode surface area on pacing threshold were assessed in two substudies. The effects of intra-oesophageal local anaesthesia and of two different pacing wave configurations on pacing threshold and discomfort were also assessed. Substudy I comprised 16 subjects (3 patients with a history of paroxysmal supraventricular tachycardia and 13 healthy volunteers) and substudy II comprised 16 healthy volunteers. TAS was performed using a hexapolar luminal prototype oesophageal electrode catheter. In substudy I bipolar pacing was performed in the semi-supine and left decubitus body positions for different pulse durations (20, 10, 6 and 2 ms), interelectrode pole distances (10 to 24 mm) and electrode pole surface areas (0.22 to 0.66 cm2). In substudy II TAS was performed with square wave and triangular waveform pulses after intra-oesophageal saline and lidocaine 20 mg/ml. These solutions were given in random order. Neither the interelectrode distance nor electrode surface areas had any significant influence on pacing thresholds. Stimulation thresholds were not affected by body position. Intraoesophageal lidocaine did not affect the discomfort experienced. Peak pacing thresholds using a triangular waveform were significantly higher than thresholds using a square waveformn (p < 0.001). The optimal pacing technique for TAS remains to be defined. The TAS-induced pain is probably not generated from the oesophageal mucous membrane. There is a significant difference in pacing thresholds between triangular and square waveforms.     

Coronary sinus dissection during left ventricular pacing electrode implantation.

Coronary sinus (CS) dissection during biventricular pacing electrode implantation is a complication that rarely develops. A 71-year-old female with recurrent ventricular tachycardia, heart decompensation, and poor left ventricular function because of dilated cardiomyopathy was admitted for the implantation of a cardioverter-defibrillator for biventricular pacing. During the operation, we experienced a CS dissection with hematoma in the left ventricle wall while introducing the guidance catheter into the CS. However, the pacing lead was successfully implanted into the posterolateral vein using the "over-the-wire" technique. The postoperative electrocardiogram showed a decreased QRS; meanwhile, the echocardiography revealed dimensional reduction and functional improvement of the left ventricle.     

The impact of intra-aortic balloon pumping on cardiac output determination by pulmonary arterial and transpulmonary thermodilution in pigs

OBJECTIVE: The aim of this study was to evaluate the impact of intra-aortic balloon pumping (IABP) on the comparison of simultaneous measurements of cardiac output via pulmonary arterial and transpulmonary thermodilution (PiCCO; Pulsion Medical Systems, Munich, Germany). DESIGN: Prospective. SETTINGS: University research laboratory. PARTICIPANTS: The data were derived from 9 anesthetized (fentanyl, propofol, flunitrazepam, rocuronium) and ventilated pigs. INTERVENTIONS: A thermodilution catheter was inserted into the pulmonary artery, a PiCCO catheter into the abdominal aorta through the right femoral artery, epicardial atrial pacing wires through a thoracotomy, and a balloon catheter for counterpulsation into the descending thoracic aorta through the left femoral artery. Cardiac output was varied over a wide range by cardiac pacing between 80 and 150/min in steps of 10/min and was measured without and during IABP at an assist frequency of 1:1. MEASUREMENTS AND MAIN RESULTS: A total of 236 paired cardiac output measurements were carried out in a range of cardiac output between 1.4 to 4.9 L/min. A close correlation was found between transpulmonary and pulmonary arterial thermodilution both without and during IABP (r = 0.94 and 0.93, respectively) and a good agreement of both methods (bias of 0.30 and 0.26 L/min, respectively; precision 0.47 and 0.52 L/min, respectively). CONCLUSIONS: Transpulmonary thermodilution is suitable for cardiac output measurement during IABP. Hence, in critically ill patients with cardiac pump failure, blood flow may be determined as accurately with the less-invasive transpulmonary method as with the traditional pulmonary arterial thermodilution one.     

Epicardial left ventricular lead placement for cardiac resynchronization therapy: optimal pace site selection with pressure-volume loops

OBJECTIVES: Patients in heart failure with left bundle branch block benefit from cardiac resynchronization therapy. Usually the left ventricular pacing lead is placed by coronary sinus catheterization; however, this procedure is not always successful, and patients may be referred for surgical epicardial lead placement. The objective of this study was to develop a method to guide epicardial lead placement in cardiac resynchronization therapy. METHODS: Eleven patients in heart failure who were eligible for cardiac resynchronization therapy were referred for surgery because of failed coronary sinus left ventricular lead implantation. Minithoracotomy or thoracoscopy was performed, and a temporary epicardial electrode was used for biventricular pacing at various sites on the left ventricle. Pressure-volume loops with the conductance catheter were used to select the best site for each individual patient. RESULTS: Relative to the baseline situation, biventricular pacing with an optimal left ventricular lead position significantly increased stroke volume (+39%, P =.01), maximal left ventricular pressure derivative (+20%, P =.02), ejection fraction (+30%, P =.007), and stroke work (+66%, P =.006) and reduced end-systolic volume (-6%, P =.04). In contrast, biventricular pacing at a suboptimal site did not significantly change left ventricular function and even worsened it in some cases. CONCLUSIONS: To optimize cardiac resynchronization therapy with epicardial leads, mapping to determine the best pace site is a prerequisite. Pressure-volume loops offer real-time guidance for targeting epicardial lead placement during minimal invasive surgery.     

Prevention of cardiovascular diseases - a scientific dilemma

In order to improve the technique of transoesophageal atrial stimulation (TAS), the effects of body position, interelectrode spacing and electrode surface area on pacing threshold were assessed in two substudies. The effects of intra-oesophageal local anaesthesia and of two different pacing wave configurations on pacing threshold and discomfort were also assessed. Substudy I comprised 16 subjects (3 patients with a history of paroxysmal supraventricular tachycardia and 13 healthy volunteers) and substudy II comprised 16 healthy volunteers. TAS was performed using a hexapolar luminal prototype oesophageal electrode catheter. In substudy I bipolar pacing was performed in the semi-supine and left decubitus body positions for different pulse durations (20, 10, 6 and 2 ms), interelectrode pole distances (10 to 24 mm) and electrode pole surface areas (0.22 to 0.66 cm²). In substudy II TAS was performed with square wave and triangular waveform pulses after intra-oesophageal saline and lidocaine 20 mg/ml. These solutions were given in random order. Neither the interelectrode distance nor electrode surface areas had any significant influence on pacing thresholds. Stimulation thresholds were not affected by body position. Intra-oesophageal lidocaine did not affect the discomfort experienced. Peak pacing thresholds using a triangular waveform were significantly higher than thresholds using a square waveform (p &;lt; 0.001). The optimal pacing technique for TAS remains to be defined. The TAS-induced pain is probably not generated from the oesophageal mucous membrane. There is a significant difference in pacing thresholds between triangular and square waveforms.     

Influence of atrioventricular synchrony on hemodynamics in patients with normal and low ejection fractions following open heart surgery

The authors wished to test the hypothesis that atrioventricular synchrony has a relatively greater effect on hemodynamic parameters in postoperative patients with low ejection fractions compared to those with normal ejection fractions. Temporary pacing wires were placed on the right atrium and right ventricle of patients undergoing open heart surgery. Duplicate thermodilution cardiac outputs were determined during atrial pacing and ventricular pacing at 100 beats/min. Mean left atrial and systemic blood pressures were monitored. Thirteen patients with ejection fractions of 45 per cent or less (range 24 to 45%, mean 37.3%) were included in the low ejection fraction group, and 27 patients with ejection fractions of 59 per cent or greater (range 59 to 80%, mean 66.8%) were considered in the normal ejection fraction group. All hemodynamic parameters improved significantly when changing from ventricular pacing to atrial pacing in both the normal ejection fraction group and low ejection fraction group (P less than 0.05). The magnitude of change between the groups showed no significant difference for all parameters except left atrial pressure, which decreased by a greater percentage in the low ejection fraction group with atrial pacing (P less than 0.001). The atrial contribution to hemodynamic enhancement is important in patients with normal and low ejection fraction following open heart surgery. Patients with low ejection fractions do not sustain a relatively greater reduction in cardiac output, stroke volume index, or systemic blood pressure with loss of atrioventricular synchrony when compared to patients with normal ejection fractions.