Temporary pacemaker use during coronary arteriography

Transcoronary pacing in an animal model : Second coated guidewire versus cutaneous patch as indifferent electrodes

BACKGROUND

Transcoronary pacing is a seldom used treatment option for unheralded bradycardias in the setting of percutaneous coronary interventions (PCI). In the present study we compared a coated guidewire inserted proximally into a coronary artery with a cutaneous patch electrode as indifferent electrodes for transcoronary pacing in a porcine model.

METHODS

Transcoronary pacing was investigated in 7 adult pigs in an animal catheterization laboratory. A standard guidewire insulated by a monorail-balloon was advanced into the periphery of a coronary artery serving as the cathode. As the indifferent anode, a special guidewire with electrical insulated by a polytetrafluoroethylene (PTFE) coating was positioned into the proximal part of the same coronary vessel. Transcoronary pacing parameters (threshold and impedance data and the magnitude of the epicardial electrogram) were compared with unipolar transcoronary pacing using a cutaneous patch electrode.

RESULTS

Transcoronary pacing was successful against both indifferent electrodes. Pacing thresholds obtained with the coated guidewire technique (1.8 ± 1.3 V) were similar to those obtained by standard unipolar transcoronary pacing with a cutaneous patch electrode (1.8 ± 1.5 V). The impedance with the additional coated guidewire was 419 ± 144 Ω and thereby slightly higher compared to 320 ± 103 Ω obtained by pacing against the patch electrode (p < 0.05). Both settings yielded comparable R‑wave amplitudes (8.0 ± 5.1 mV vs. 7.1 ± 3.6 mV).

CONCLUSIONS

A second coated guidewire is as effective as a cutaneous patch electrode when added as an indifferent electrode in transcoronary pacing. This transcoronary pacing technique could replace temporary transvenous pacing in emergency situations during PCI, especially when using the radial approach.

Transcoronary pacing : Reliability during myocardial ischemia and after implantation of a coronary stent

BACKGROUND

Transcoronary pacing is a useful therapeutic option for the treatment of unheralded bradycardias in the setting of percutaneous coronary interventions (PCI).

OBJECTIVES

In the present study, we investigated the influence of stent implantation and transient myocardial ischemia on the feasibility of transcoronary pacing in a porcine model.

METHODS

7 adult pigs underwent a percutaneous coronary intervention with implantation of a coronary stent under general anaesthesia in an animal catheterization laboratory. Transcoronary pacing was established by using a standard guidewire isolated with an angioplasty balloon positioned in the periphery of the right coronary artery serving as the cathode. As the indifferent anode, a skin patch electrode at the back of the animal was used. The reliability of transcoronary pacing was assessed by measurement of threshold and impedance data and the magnitude of the epicardial electrogram at baseline, after implantation of a coronary stent and finally during myocardial ischemia.

RESULTS

Effective transcoronary pacing could be demonstrated in all cases with the standard unipolar transcoronary pacing setup yielding a low pacing threshold at baseline of 1.3 ± 0.8 V with an impedance of 283 ± 67 Ω. Implantation of a coronary stent did not influence the pacing threshold (1.0 ± 0.4 V) and impedance (262 ± 63 Ω). Acute myocardial ischemia lead to a significant but clinically nonrelevant increase of the pacing threshold to 2.0 ± 0.6 V and a drop in pacing impedance (137 ± 39 Ω).

CONCLUSIONS

Transcoronary pacing in the animal model is not affected by implantation of a coronary stent in the same vessel used for pacing. Despite a significant increase in pacing threshold, the transcoronary pacing approach is reliable in acute myocardial ischemia during a percutaneous coronary intervention.

Temporary Left Ventricular Pacing: A Desperate Life-saving Measure in Emergency Situation

Transcutaneous or transvenous pacing of the right ventricle is performed as a routine practice for patients received with symptomatic bradycardia or complete heart block with relative ease in cath lab. However, more and more patients are received with multiple comorbidities, critical condition, and difficult vascular access. In this article, we describe a patient with difficult venous access with tricuspid regurgitation and displaced the right ventricular pacemaker temporary lead undergoing coronary angiography who was managed with emergent nonconventional left ventricular pacing.

The double guidewire approach for transcoronary pacing in a porcine model

BACKGROUND

Transcoronary pacing is used for treatment of unheralded bradycardias in the setting of percutaneous coronary interventions (PCI).

OBJECTIVES

In the present study we introduced a new concept - the double guidewire approach - for transcoronary pacing in a porcine model.

METHODS

Transcoronary pacing was applied in 16 adult pigs under general anaesthesia in an animal catheterization laboratory. A special guidewire with electrical insulation by PTFE coating except for the distal part of the guidewire was positioned in the periphery of a coronary artery serving as the cathode. As the indifferent anode, an additional standard floppy tip guidewire was advanced into the proximal part of the same coronary vessel. The efficacy of double guidewire transcoronary pacing was assessed by measurement of threshold and impedance data and the magnitude of the epicardial electrogram compared with unipolar transcoronary pacing using a standard cutaneous patch electrode as indifferent anode.

RESULTS

Transcoronary pacing was effective in all cases. Pacing thresholds obtained with the double guidewire technique (1.5 ± 0.9 V) were similar to those obtained by standard unipolar transcoronary pacing with a cutaneous patch electrode (1.2 ± 0.7 V) and unipolar transvenous pacing against the same cutaneous patch electrode (1.5 ± 1.0 V). Bipolar transvenous pacing yielded the lowest pacing threshold at 0.8 ± 0.4 V.

CONCLUSIONS

Transcoronary pacing in the animal model with the novel "double guidewire approach" is a simple and effective pacing technique with comparable pacing thresholds obtained by standard unipolar transcoronary and transvenous pacing.

A novel minimal invasive closed chest myocardial ischaemia reperfusion model in rhesus monkeys (Macaca mulatta): improved stability of cardiorespiratory parameters

The aim of this study was to report the cardiorespiratory events observed during coronary artery occlusion and reperfusion in a minimally invasive closed chest myocardial occlusion-reperfusion model in rhesus monkeys. We hypothesized that a minimally invasive technique may lead to fewer cardiac arrhythmias and complications. Eight male rhesus macaques 10-15 kg and 10-15 years old were sedated with ketamine (2 mg/kg), midazolam (1.3 mg/kg), atropine (0.01 mg/kg) and buprenorphine 0.02 mg/kg intramuscularly. Etomidate 1-2 mg/kg was injected intravenously to allow tracheal intubation. Anaesthesia was maintained with isoflurane. Pulse oximetry, electrocardiogram (ECG), heart rate, mean arterial blood pressure (MAP), inspired isoflurane fractions (F(I)ISO) and core temperature were recorded every 10 min. The coronary artery occlusion was induced by a balloon-tipped catheter advanced via the femoral artery into the left anterior descending artery and inflated to completely occlude the vessel for 20-50 min (IT) before reperfusion. Sequences of elevated ST segment, QRS complex prolongation, ventricular premature complexes and ventricular fibrillation were observed with a lower incidence than previously described in the literature. IT was (min: 17; max: 50) min long. F(I)ISO was lower than the minimal alveolar concentration in these species. Hypotension (MAP < 70 mmHg) and hypothermia (T°C < 36°C) were observed in all macaques. This minimally invasive closed chest model was successful in providing better cardiorespiratory physiological parameters than reported in previous models. The benefit (achieving ischaemia) versus risk (lethal arrhythmia) of the duration of the coronary occlusion should be considered.

Temporary transcoronary pacing by coated guidewires

Relevant bradycardias during percutaneous coronary intervention (PCI) are a rare event, but they require immediate therapy by temporary pacing. However, transvenous pacing is associated with frequent and severe complications. Therefore, we wanted to evaluate the safety and reliability of trans-coronary pacing by means of a PCI guidewire. Coronary pacing was applied to 70 consecutive patients undergoing PCI. Pacing was performed before and after PCI in a unipolar setting using standard guidewires as a cathode and a skin electrode as an anode. Both were connected to an external pacemaker. Coronary pacing (maximum output at 10 V, impulse duration 2.5 ms) was effective in 60 of 70 patients (85.7%). Successful pacing was achieved in the LAD and diagonal branches in 90% (27 of 30 Pts.), in the LCX and marginal branches 84.2% (16 of 19 Pts.) and in the RCA in 81% (17 of 21 Pts.). Pacing thresholds were comparable in all vessels within a range of 1-10 V averaging 6.6 +/- 2.3 V before and 6.6 +/- 2.2 V after PCI. The impedance ranged from 190-544 Omega with mean pacing impedance for coronary pacing of 424 Omega before and 416 Omega after PCI, respectively. Significant bradycardias during PCI occurred in 7 cases (10%). In three cases (4.3%) temporary coronary pacing became necessary at a maximum pacing duration of 3 min. There were no severe side effects. Coronary spasm occurred in 3 cases (4.3%) after pacing and was promptly reversible after intracoronary application of nitroglycerine. It is concluded that coronary pacing is a safe and feasible method for the treatment of bradycardias during PCI. It avoids additional venous puncture under hemodynamically unstable conditions and subsequent transvenous pacing, which is accompanied by potentially severe complications and additional costs.

Transient left bundle branch block induced by left-sided cardiac catheterization in patients without pre-existing conduction abnormalities

A traumatic left bundle branch block (LBBB) is uncommon in a patient with intact atrioventricular conduction. Three of our patients developed LBBB during a left-sided catheterization. Two patients suffered from angina pectoris and the other had an abdominal aneurysm. Two of them had a history of hypertension. None of the patients had ever shown any conduction abnormalities before the catheterization. The electrocardiogram just before the examination was normal in all 3 patients. LBBB was observed when a catheter was introduced into the left ventricle, and lasted 2--4 min without significant change in heart rates. Examination revealed no significant stenosis proximal to the first septal perforator and normal left ventricular contraction in all patients. One patient developed permanent LBBB 14 months later. Catheter-induced LBBB may occur easily with certain anatomical characteristics of the left bundle branch or the distal His bundle, with or without some concealed damage to the conduction system. It is important to keep this complication in mind and to pay adequate attention to patients' electrocardiograms as well as their angiographical findings, especially in those with pre-existing right bundle branch block.

Successful coronary pace-termination of ventricular tachycardia during coronary angioplasty

Coronary pacing has been performed to treat bradycardias occurring during percutaneous transluminal coronary angioplasty (PTCA) using an angioplasty guidewire. We describe a case of a 62-year-old man who developed ventricular tachycardia (VT) during PTCA. The tachycardia was successfully terminated by overdrive pacing via an angioplasty guidewire.

Transient loss of sensing and capture during coronary angiography in two patients with permanent pacemakers

Two cases of transient pacemaker failure to sense and capture during angiography are reported. This phenomenon is due to a transient increase in sensing and pacing thresholds beyond the pacemakers programmed settings. The underlying mechanism may be related to blood displacement, the electrochemical properties of the injectate, the high concentration of the contrast media, or a combination of these properties. Even though the chambers in which sensing and pacing loss occurred differed (ventricle in the first and atria in the second), the episode occurred repeatedly after injection of contrast media into the artery supplying the respective electrode-tissue interface. In pacemaker dependent patients, provisions for external pacing should be implemented prior to injection of contrast into the coronary arteries.

Complete heart block complicating retrograde left ventricular catheterization: case report and review

Complete heart block (CHB) following retrograde left ventricular catheterization is uncommon. We report a case of transient CHB in a patient with severe aortic stenosis and bifascicular block on the baseline surface electrocardiogram during retrograde left ventricular catheterization. The block resolved spontaneously without sequelae. A review of the literature using MedLine was performed and recommendations for temporary and permanent pacing are outlined.

Coronary and left ventricular pacing as standby in invasive cardiology

Coronary pacing using as unipolar negative electrode a guidewire placed in a coronary branch was tested in 349 sites of 300 consecutive patients undergoing coronary angioplasty. It was possible for 339 sites (97%). The threshold currents ranged from 1 to 15 (mean +/- standard deviation 3.4 +/- 2.4) mA. Side effects were seen in 13 patients (4%): 6 (2%) had transient coronary spasm, 4 (1%) had diaphragmatic stimulation, and 3 (1%) had stinging pain at the skin electrode. Of the 10 cases with pacing failure, left ventricular pacing was successfully tested in 5 by introducing the coronary wire or another wire into the left ventricle. It yielded a threshold of 2-8 (3.2 +/- 2.7) mA. Therapeutic pacing for significant bradycardia was required in 7 patients (2%). It was successful in all. Coronary or left ventricular pacing appears to be a simple and reliable temporary measure. When there is no wire in the coronary artery or for diagnostic catheterization, left ventricular pacing can be done using the same setup and any type of guidewire.

Complete atrioventricular block during cardiac catheterization: two cases reports in patients without pre-existing conduction abnormalities

Third-degree atrioventricular block has been well documented during ventricular catheterization of patients with underlying conduction abnormalities. Two cases reported here describe patients with normal conduction at baseline who sustained complete heart block during ventricular catheterization. Catheterizing physicians should be aware of this risk, which has not been previously reported.

Significance of ventricular tachyarrhythmias complicating cardiac catheterization: a CASS Registry Study

Ventricular tachycardia and ventricular fibrillation are recognized complications of cardiac catheterization. Despite numerous reports documenting the frequency of these occurrences, their significance has not been systematically examined. Accordingly, the outcome of 108 patients who experienced either ventricular tachycardia or ventricular fibrillation during coronary angiography between 1975 and 1979 in the Coronary Artery Surgery Study (CASS) Registry were examined. There were 20,142 patients analyzed. Patients with ventricular tachyarrhythmias had more objective evidence of left ventricular impairment, clinical heart failure, and ventricular arrhythmia recorded as a clinical symptom. The overall 5-year survival rates were 83% and 88% for patients with and without ventricular tachyarrhythmias, respectively (p = 0.07). When ventricular function, age, gender, angina, and previous myocardial infarction were added in a stepwise Cox survival analysis, the presence of arrhythmias was not significant (p = 0.66). At 5 years, 80% of the medically treated patients and 82% of the surgically treated patients remained alive (p = 0.95). The only statistically significant differences in the patients with ventricular arrhythmias who were treated medically or surgically were age (medically treated patients 52 +/- 10 years, surgical patients 57 +/- 9 years, p = 0.01) and number of diseased vessels (p less than 0.001). In a stepwise Cox survival analysis, functional impairment secondary to congestive heart failure was the only significant covariate to affect survival in the medical and surgical groups (p = 0.0001). Surgical therapy itself was not significant (p = 1.00). The incidence of sudden death during 5 years for patients with and without ventricular tachyarrhythmias during catheterization was 5% and 4%, respectively (p = 0.28).(ABSTRACT TRUNCATED AT 250 WORDS)

Reduction of ventricular arrhythmias by atropine during coronary arteriography

Sustained ventricular arrhythmia is a well-recognized complication of cardiac catheterization, often occurring after selective coronary artery injection of contrast medium. The role of autonomic reflexes in the pathogenesis of this phenomenon is unclear. Although the muscarinic antagonist atropine is often administered prophylactically before coronary angiography to reduce the likelihood of sinus bradycardia and vasovagal reactions, its influence on ventricular arrhythmias in this setting has not been established. This case-control trial studied 648 patients undergoing coronary arteriography to investigate this issue. Eleven case subjects (those with ventricular tachyarrhythmia) were identified. Control subjects (those without ventricular tachyarrhythmia) were matched for baseline heart rate (+/- 6 beats/min), age (+/- 10 years), sex and calendar year of procedure using a 1:3 sampling ratio. All 26 potential clinical, anatomic and hemodynamic covariates were statistically similar between groups. Ventricular tachyarrhythmias were more likely to occur after selective right coronary injection (odds ratio 15.1, p = 0.0008) but not after multiple contrast injections (odds ratio 0.918, difference not significant). Most importantly, atropine sulfate was administered prophylactically to 18 of 33 control subjects (55 +/- 9%) but only 1 of 11 cases (9 +/- 9%), generating a significant odds ratio of 12.0 (p = 0.02). Thus, the odds of experiencing sustained ventricular tachyarrhythmias during coronary arteriography may potentially be reduced 12-fold by prior administration of atropine, even in patients with normal baseline heart rates.

Use of balloon flotation pacing catheters for prophylactic temporary pacing during diagnostic and therapeutic catheterization procedures

The use of prophylactic temporary pacemakers during diagnostic catheterization, coronary angioplasty and percutaneous balloon valvuloplasty was investigated retrospectively over an 18-month period. Balloon flotation temporary pacemaker leads were placed in 193 (12%) of 1,609 patients undergoing diagnostic catheterization, 641 (65%) of 993 patients undergoing coronary angioplasty and 199 (100%) of 199 patients undergoing aortic or mitral valvuloplasty. There were no perforations or significant arrhythmic complications related to pacemaker placement in these 1,033 cases, and pacing was initiated promptly when required by withdrawal of the catheter tip into the right ventricle. Significant bradycardia or new conduction defects developed in 17 patients (1%) during diagnostic catheterization, 10 patients (1%) during angioplasty and 20 patients (10%) during valvuloplasty, but were severe enough to require initiation of temporary pacing in only 1 (0.06%), 4 (0.4%) and 5 (2.5%) patients, respectively. No patient undergoing diagnostic catheterization or angioplasty (but 5 patients undergoing valvuloplasty) required immediate pacing support to treat a life-threatening bradycardia. The total cost of prophylactic pacemakers was $103,300, with a cost per actual use of $19,300 for diagnostic cases, $16,025 for angioplasty and $3,980 for balloon valvuloplasty. These data suggest that prophylactic temporary pacing is not indicated during either diagnostic catheterization or coronary angioplasty, but should be used routinely during balloon valvuloplasty.

Chronic bundle branch block and use of temporary transvenous pacemakers during coronary arteriography

A retrospective analysis of 217 consecutive patients with chronic bundle branch blocks undergoing cardiac catheterization was done to evaluate the need for temporary transvenous pacing during coronary arteriography. In patients without temporary right ventricular pacemakers (n = 185), only one episode of high-grade atrioventricular block occurred during coronary arteriography which required the urgent use of temporary pacing. All other bradyarrhythmias, including five episodes of transient asystole (greater than 3-sec pause) and four episodes of atrioventricular block (second degree or higher) were successfully managed without pacemaker utilization. Patients with prophylactic right ventricular pacemakers (n = 32) had a greater prevalence of ventricular fibrillation than those without pacing electrodes located in the right ventricle (2% vs. 9% respectively; P less than 0.05). These findings suggest that routing prophylactic pacemaker insertion during coronary arteriography in patients with chronic bundle branch block is not warranted and may place the patient at risk for developing iatrogenic ventricular arrhythmias.

Use of temporary pacemakers during coronary angioplasty: an evolving experience with ventricular fibrillation in 400 cases

Because of a perceived high frequency of ventricular fibrillation when a pacemaker catheter was placed in the right ventricular apex during PTCA, we reviewed our first 400 cases for this complication. The incidence of ventricular fibrillation in the entire group was 10 of 400 cases (2.5%) compared with 17 of 3,806 (0.4%) diagnostic coronary arteriograms performed in our laboratory during the same time period (P less than .001). Ventricular fibrillation occurred more frequently during PTCA when the pacemaker catheter tip was placed in the right ventricular apex (8 of 63 cases, 12.6%) than when it was positioned in either the pulmonary artery, vena cava, or when a pacemaker catheter was not used (2 of 337 cases, 0.6%, P less than .001). Based on these data we have developed a policy of inserting temporary pacemakers prophylactically during PTCA only for patients undergoing dilation of dominant right or dominant left circumflex coronary arteries and in patients with acute myocardial infarction.