Biventricular pacing 18 months after Batista operation

We conducted biventricular pacing in a patient with dilated cardiomyopathy and complete left bundle branch block who had recurrent heart failure and mitral valve regurgitation 18 months after partial left ventriculectomy and mitral valve repair. An epicardial lead was fixed on the left ventricular free wall surgically through a thoracotomy, and the other two leads were implanted transvenously. Biventricular pacing restored contractile synchrony and led to more efficient left ventricular contraction and reductions in mitral regurgitation. Biventricular pacing may produce beneficial effects for patients with the recurrent intractable heart failure associated with cardiomyopathy and complete left bundle branch block after partial left ventriculectomy.     

Biventricular pacing in a patient with severe congestive heart failure

We report a case of dilated cardiomyopathy with severe congestive heart failure (ejection fraction: 19%) and complete left bundle branch block (QRS duration: 240 ms) 13 years after aortic valve replacement. Permanent biventricular pacing was implanted by inserting a left ventricular lead thorough a small left thoracotomy following intravenous insertion of right atrial and ventricular endocardial leads. Biventricular pacing increased hemodynamic parameters such as blood pressure, cardiac output and decreased mitral regurgitation. Symptoms and exercise tolerance improved dramatically. Left ventricular epicardial lead insertion via a small thoracotomy is thus useful in selected patients.     

Anesthetic management of a patient with dilated cardiomyopathy for left ventricular pacing lead insertion under video-assisted thoracic surgery

A 54-year-old man with dilated cardiomyopathy treated with diuretics, alpha-beta blockers, antiarrhythmics for the previous 5 years, had the indication for biventricular pacing and was scheduled for placing of pacing leads in his left ventricular wall under video-assisted thoracic surgery. Preoperative tests revealed first degree A-V block with left bundle branch block and left ventricular dilation with an ejection fraction of 0.11 on echocardiography. Anesthesia was induced with ketamine and midazolam. Endotracheal intubation was facilitated by administration of vecuronium. Anesthesia was maintained with oxygen-sevoflurane and fentanyl. One lung ventilation was carried out during surgery and the arterial oxygen saturation was kept satisfactory with the intermittent insuffilation of oxygen to the non ventilated lung. The procedure was completed uneventfully while ventricular tachycardia was observed. Biventricular pacing increased the ejection fraction from 0.11 to 0.27. We conclude that any special monitoring such as TEE would be helpful to evaluate the cardiac function during the operation.     

Biventricular pacing

QRS widening has important clinical and prognostic implications in patients with chronic heart failure. Ventricular conduction abnormalities such as a left bundle branch block, cause ventricular dysynchrony and several hemodynamic disadvantages. The presence of ventricular dysynchrony results in abnormal wall motion, impaired ventricular contractility, decreased ventricular filling, and increased mitral regurgitation. Biventricular pacing has been recently proposed as an adjunct therapy for advanced heart failure in patients with ventricular conduction abnormalities. Biventricular pacing acutely increases the + dP/dt of left ventricle, the systolic blood pressure and the pulse pressure, prolongs the diastolic left ventricular filling time, shortens the mitral regurgitation duration, and reduces the pulmonary wedge pressure. The implantation of biventricular pacemaker results in improvements of the functional class, exercise capacity, quality of life, echocardiographic findings, and neurohormonal data. Although the indication for biventricular pacing has not yet established, patients with functional class III or IV and left bundle branch block or left ventricular conduction delay showing QRS duration > or = 150 ms are good candidates.     

Systolic left ventricular apical bulging after biventricular pacing mimicking takotsubo cardiomyopathy

Resolution of the issue of nonresponsiveness to cardiac resynchronization therapy (CRT) remains crucial to the successful treatment of conduction disturbances in heart failure. In this study, a patient with refractory heart failure including left bundle branch block was treated via surgical CRT. The epicardial left ventricular (LV) lead, implanted using thoracoscopic guidance, was unexpectedly located on the apical side. Echocardiographic findings of the LV motion mimicked takotsubo cardiomyopathy. The LV lead was successfully re-implanted along a lateral branch of the cardiac vein using an endovascular approach, resulting in restored contractility and reversal of the LV remodeling.     

Acute Hemodynamic Effects of Cardiac Resynchronization Therapy in Patients with Poor Left Ventricular Function During Cardiac Surgery

Abstract   Background: Cardiac resynchronization therapy improves systolic function in patients with heart failure and left ventricular (LV) dyssynchrony. However, the effect of biventricular (BiV) pacing on perioperative hemodynamics in cardiac surgery is not well known. We investigated the acute hemodynamic response using LVdP/dt_max in patients with depressed LV function and conduction disturbances undergoing cardiac surgery. Methods: Patients with LV ejection fraction of ≤35%, QRS duration of >130 ms, and left bundle branch block undergoing aortocoronary bypass and valve surgery were included. Temporary atrial and left and right ventricular pacing wires were applied, and LVdP/dt_max was measured with a high fidelity pressure wire in the left ventricle at the end of cardiopulmonary bypass. Responders had a ≥10% increase in LVdP/dt_max. Results: Eleven patients (age 63 ± 11 years, eight males) with a LV ejection fraction 0.29 ± 0.06% were included. Compared with right ventricular pacing (782 ± 153 mmHg/sec), there was a significant improvement in the mean LVdP/dt_max during simultaneous BiV pacing (849 ± 174 mmHg/sec; p = 0.034) and sequential BiV pacing with the LV 40 ms advanced (880 ± 157 mmHg/sec; p = 0.003). Improvement during LV pacing alone was not significant (811 ± 141 mmHg/sec). Six patients were responders with simultaneous and nine with sequential BiV pacing. Only sequential BiV pacing had a significant improvement in LV systolic pressure (p = 0.02). Conclusions: BiV pacing results in acute hemodynamic improvement of LV function during cardiac surgery. Optimization of the interventricular pacing interval contributes to the effect of the therapy.     

Cardiac resynchronization therapy: device-based medicine for heart failure

Cardiac resynchronization therapy (CRT) or biventricular pacing is a novel adjunctive therapy for patients with advanced heart failure (HF). Many patients with severe HF have a left bundle branch block or an intraventricular conduction delay, with up to 25% of patients with a QRS > 120 ms, resulting in significant left ventricular (LV) dyssynchrony and a high mortality rate. The efficacy of CRT is based on the reduction in the conduction delay between the two ventricles and optimization of the ejection fraction, decrement in mitral regurgitation, LV remodeling, thus resulting in symptom improvement. Cardiac resynchronization therapy can be achieved both transvenously using a coronary sinus branch, or epicardially. Clinical trials have demonstrated a significant improvement in the NYHA class and the exercise capacity as well as a marked reduction in the hospitalization rate. More recently, the COMPANION trial showed a 43% reduction in a composite endpoint of all-cause mortality and hospitalization in the group receiving a CRT device in combination with an implantable cardiac defibrillator (ICD). Thus, management of patients with reduced LV function, wide QRS, and symptomatic refractory HF, despite optimal drug therapy, should include CRT as an option. The adjunct of an ICD combined with CRT should be considered if the LV ejection fraction (ischemic cardiomyopathy) is <30%. There are still significant unanswered questions regarding the nonresponder population and the role of tissue Doppler imaging techniques, the impact of CRT on total mortality and CRT in dilated cardiomyopathy or chronic atrial fibrillation. The use CRT postoperatively or at time of cardiac surgery, as well as new epicardial approaches using a thoracoscopic approach or robotically assisted surgery in patients not suitable for coronary vein leads are challenging topics to address in the years to come.     

Cardiomyopathy induced by artificial cardiac pacing: myth or reality sustained by evidence?

Implantable cardiac pacing systems are a safe and effective treatment for symptomatic irreversible bradycardia. Under the proper indications, cardiac pacing might bring significant clinical benefit. Evidences from literature state that the action of the artificial pacing system, mainly when the ventricular lead is located at the apex of the right ventricle, produces negative effects to cardiac structure (remodeling, dilatation) and function (dissinchrony). Patients with previously compromised left ventricular function would benefit the least with conventional right ventricle apical pacing, and are exposed to the risk of developing higher incidence of morbidity and mortality for heart failure. However, after almost 6 decades of cardiac pacing, just a reduced portion of patients in general would develop these alterations. In this context, there are not completely clear some issues related to cardiac pacing and the development of this cardiomyopathy. Causality relationships among QRS widening with a left bundle branch block morphology, contractility alterations within the left ventricle, and certain substrates or clinical (previous systolic dysfunction, structural heart disease, time from implant) or electrical conditions (QRS duration, percentage of ventricular stimulation) are still subjecte of debate. This review analyses contemporary data regarding this new entity, and discusses alternatives of how to use cardiac pacing in this context, emphasizing cardiac resynchronization therapy.     

Perioperative risk of complete heart block in patients with bifascicular block and prolonged PR interval.

Because there is a paucity of information on the perioperative risk of developing complete heart block among patients with bifascicular block (either right bundle branch block and left anterior hemiblock or left bundle branch block) and a long PR interval on the surface electrocardiogram, we undertook an analysis of 76 such patients. Twenty-three patients had right bundle branch block and left axis deviation with a long PR interval and 53 had left bundle branch block with along PR interval. Thirty patients had 37 general anaesthetics, 23 had 32 spinal anaesthetics, and 50 had 64 local anaesthetics or endoscopic procedures. No patient developed complete heart block. Four patients developed sinus bradycardia during general anaesthetics, responsive to atropine or isoproterenol. Similarly, none of the 23 such patients in the literature reviewed had developed complete heart block. Because placement to temporary pacemakers is not without risk, we conclude that prophylactic pacing is not necessary in asymptomatic patients with bifascicular block even in the presence of a long PR interval. Since we did not study patients with recent syncope or myocardial infarction, caution should be exercised in applying these results to such patients.     

Coronary artery spasm immediately after insertion of a laryngeal mask airway during induction of general anesthesia

We describe the case of a 73-year-old woman scheduled for tendon sheath release for carpal tunnel syndrome under general anesthesia. Preoperatively, she had hypertension and complete right bundle branch block with normal left ventricular function. During general anesthetic induction, immediately after insertion of the laryngeal mask airway, her electrocardiogram (ECG) showed remarkable ST segment elevation followed by complete atrio-ventricular block. Transcutaneous cardiac pacing was immediately started and nitroglycerin was administered. Nine minutes after starting cardiac pacing, the level of the ST segment and heart rate returned to baseline. The surgical procedure was postponed and the patient was admitted to the coronary care unit. Thereafter, her ECG remained normal. Coronary artery spasm was suspected due to the transient nature of the cardiac symptoms, although the cause of the spasm was not clear. Coronary artery spasm can occur even in patients with relatively low cardiovascular risks. Hence, it is essential to be vigilant about all kinds of circulatory changes, including ECG changes, and to be prepared with the drugs and devices required to deal with sudden untoward cardiac events.     

Complete atrioventricular block during anesthesia

PURPOSE: To describe a case of asymptomatic first degree atrioventricular block with a bifascicular block that progressed to complete atrioventricular block during anesthesia. This potentially fatal block was successfully treated with transesophageal ventricular pacing. CLINICAL FEATURES: A 67-yr-old man was scheduled for microvascular decompression of the right trigeminal nerve under general anesthesia. His preoperative ECG showed first degree atrioventricular block with complete right bundle branch block and left anterior hemiblock, but he had experienced no cardiovascular symptoms. Anesthesia was induced with sevoflurane 5%, and maintained with isoflurane 1.5-2% in oxygen. Fifteen minutes later in the left lateral decubitus position, the systolic arterial blood pressure suddenly decreased from 80 mmHg to 0 mmHg. Then, the ECG abruptly changed from sinus rhythm to complete atrioventricular block. The heart was unresponsive to drug therapy such as atropine 1.3 mg and isoproterenol 0.5 mg, or transcutaneous pacing but transesophageal pacing was successful. CONCLUSION: Asymptomatic first degree atrioventricular block with bifascicular block advanced to complete atrioventricular block during anesthesia. The block was successfully managed with transesophageal pacing.     

A case of complete atrioventricular block after induction of general anesthesia

A 75-year-old man with a past history of bilateral thalamic hemorrhage was scheduled for cholecystectomy and cholelithotomy under general anesthesia. Although the preoperative ECG showed a complete right bundle branch block, the echocardiogram revealed no abnormality. Anesthesia was induced with thiopental and vecuronium, and maintained with sevoflurane in oxygen. Soon after changing to the left decubitus position for the insertion of an epidural catheter, ECG showed complete atrioventricular block, which did not respond to atropine. Adrenalin was transiently effective, but arrhythmia continued. After administration of dopamine, norepinephrine and isoproterenol, we inserted a temporary transvenous pacemaker catheter, and the hemodynamics became stable by ventricular pacing. The operation was postponed. Subsequent cardiologic examination showed no ischemia. The atrioventricular block disappeared 7 hours after the induction of general anesthesia. We should be very careful with the anesthetic management of a patient with a complete right bundle branch block.     

Surgical epicardial left ventricular lead versus coronary sinus lead placement in biventricular pacing.

OBJECTIVE: Biventricular pacing has demonstrated improvement in cardiac function in treating congestive heart failure (CHF). Two different operative strategies (coronary sinus vs. epicardial stimulation) for left ventricular (LV) pacing were compared. METHODS: Since April 1999, a total of 86 patients (pts, age: 63+/-10 years) with depressed systolic LV function (mean ejection fraction 24+/-9%), left bundle-branch-block (mean QRS 182+/-22 ms) and congestive heart failure NYHA III or higher were enrolled. For biventricular stimulation coronary sinus (CS) leads were placed in 79 pts. Nine of these devices were converted to surgical epicardial LV-leads, because of CS-lead failure. In 7 patients epicardial LV-leads were initially implanted surgically, accounting for a total of 16 pts with surgical placed epicardial steroid-eluting LV-leads. For these, a limited left-lateral thoracotomy (7+/-4 cm) was used. Thirty-three (38%) pts had an indication for a defibrillator. The mean follow-up time was 16.4+/-15.4 months (0.1-45 months), representing 107.1 patient-years. RESULTS: In the biventricular pacing mode, QRS duration decreased to 143+/-16 ms (P<0.001). Threshold capture of the CS-leads increased significantly compared to surgically placed epicardial leads (18 month control: 2.2+/-1.4V/0.5 ms vs. 0.7+/-0.3V/0.5 ms), which had no increase in threshold (P<0.001). At the 18 month follow-up 7 CS-leads had a threshold of >4V/0.5 ms vs. epicardial leads which were under 1.1V/0.5 ms, except for one (1.8V/0.5 ms). After CS-lead implantation 25 LV-lead related complications occurred, (failed implantation, CS-dissection, loss of pacing capture, diaphragm stimulation or lead dislodgment), vs. one dislodgement after surgical epicardial lead placement (P<0.05). Correct lead positioning (obtuse marginal branch area) was achieved in all surgical epicardial placements but only in 70% with CS-leads (P<0.03). In the follow up period, 9 pts died (4 cardiac related). Heart transplantation was necessary in 4 pts due to deterioration of the cardiomyopathy. CONCLUSIONS: Surgical epicardial lead placement revealed excellent long-term results and a lower LV-related complication rate compared to CS-leads. Although, the approach via limited thoracotomy for biventricular pacing is associated with 'more surgery', it is a safe and reliable technique and should be considered as an equal alternative.     

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.     

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)     

Efficacy of biventricular pacing for dialysis-related hypotension due to idiopathic dilated cardiomyopathy

A 45-year-old man who had been undergoing maintenance hemodialysis for end-stage renal failure, caused by chronic glomerulonephritis 4 years before, was admitted to our hospital for biventricular pacemaker implantation (BVP). Ten years ago, he was diagnosed with idiopathic dilated cardiomyopathy, and had been suffering from dialysis-related hypotension (DRH) due to low cardiac function over the past year. An electrocardiogram revealed complete left bundle branch block with a QRS duration of 180 ms, and echocardiography showed moderate hypokinesis of the left ventricular wall and systolic asynchronized motion of the septum and free wall. After BVP, the left ventricular ejection fraction had increased from 29% to 40%, and the transmitral rapid left ventricular filling (E wave) and atrial contraction (A wave) ratio (E/A) had improved from 1.3 to 1.0. Before and after BVP, we measured hemodynamic parameters during hemodialysis by successive echocardiography. Before BVP, systemic vascular resistance had decreased, cardiac output had not changed, and hypotension was noted. In contrast, after BVP, cardiac output had increased and systemic vascular resistance had not changed, which caused an increase in blood pressure. We conclude that BVP improved the cardiac function which resulted in an improvement in dialysis-related hypotension (DRH).     

Late recovery of atrioventricular conduction after pacemaker implantation for complete heart block associated with surgery for congenital heart disease

OBJECTIVES: Pacemaker implantation is a standard recommendation for patients with persistent complete heart block following surgery for congenital heart disease. This study was performed to determine the incidence and clinical significance of late recovery of atrioventricular conduction following pacemaker implantation. METHODS: Between 1990 and 2001, 5662 open cardiac procedures for congenital heart defects were performed at our institution. The postoperative course of all patients with complete heart block in whom a permanent pacemaker was implanted was followed on a monthly basis, by either clinical or transtelephonic follow-up. RESULTS: A total of 72 patients with persistent postoperative complete heart block underwent pacemaker implantation. After insertion of the pacemaker, recovery of atrioventricular conduction was recognized in 7 of 72 patients (9.6%) at a median of 41 days (18-113 days) after the initial cardiac operation. These included 3 patients with ventricular septal defect, 2 with ventricular inversion or single ventricle, and 1 each with left ventricular outflow tract obstruction and atrioventricular septal defect. During a mean follow-up of 4.4 +/- 2.6 years, there was no late recurrence of heart block. Three patients had residual right bundle branch block and 1 had first-degree atrioventricular block. CONCLUSIONS: Atrioventricular conduction may return in a small but significant percentage of patients following pacemaker implantation for complete heart block associated with congenital heart surgery. When recovery of atrioventricular conduction occurs within the first months after surgery it appears reliable, which suggests that lifelong cardiac pacing may not be necessary in these individuals.     

A case of sudden occurrence of complete left bundle branch block during emergency surgery

We experienced a case of sudden occurrence of complete left bundle branch block during emergency surgery. A 59-year-old man suffered from facial bone fracture and eye ball injury. Repair of facial bone and removal of eye ball surgery were scheduled. Chest X-ray, echocardiography, blood counts and laboratory data were within normal limits. Awake intubation was performed. Anesthesia was maintained with 2-3% sevoflurane in 1 l x min(-1) of oxygen and 2 l x min(-1) of nitrous oxide. After induction of anesthesia, tracheostomy was performed with combined use of local anesthesia with 6 ml of 1% lidocaine with 1/200000 epinephrine. Then removal of eye ball surgery was started and finished uneventfully. During repair of facial bone fracture, we found an unexpected complete left bundle branch block. After rapid infusion of 1000 ml acetic Ringer's solution, the complete left bundle branch block disappeared. After surgery, mannitol administration at the previous hospital was noticed. Complete left bundle branch block in this case might have been induced by hypovolemia and hyperpotassemia due to osmotic diuresis by mannitol.     

The significance of bundle branch block in the immediate postoperative electrocardiograms of patients undergoing coronary artery bypass

Three hundred sixteen consecutive patients undergoing coronary artery bypass were studied for postoperative electrocardiographic conduction disturbances. Fifty-five of these 316 patients had postoperative bundle branch block (Group 1). This group had a higher incidence of left main coronary stenosis, together with previous inferior myocardial infarction, than patients without postoperative conduction disturbances (Group 2). Perioperative myocardial infarction, low cardiac output, and death were significantly more common in Group 1 than in Group 2: 7.3% versus 1.9% for perioperative myocardial infarction, 16.4% versus 2.7% for low cardiac output, and 5.5% versus 0.8% for death. Analysis of the type of conduction disturbances indicates that the presence of a new complete left bundle branch block postoperatively in a patient undergoing coronary artery bypass is a sign of intraoperative myocardial damage. This damage is potentially lethal, especially in a patient with left main coronary stenosis and previous inferior myocardial infarction.     

Temporary biventricular pacing postcardiopulmonary bypass in patients with reduced ejection fraction

BACKGROUND AND AIM: Patients with low ejection fraction (EF) undergoing myocardial revascularization frequently require ventricular pacing following cardiopulmonary bypass (CPB). While the benefits of chronic biventricular (BiV) pacing in patients with low EF are well established, there are little data on acute effects during heart surgery. This study analyzed the response of BiV versus single ventricle lead pacing on hemodynamics and left ventricular (LV) function immediately following CPB. METHODS: Ten patients with decreased LV EF (mean = 35 +/- 6%) underwent open-heart surgery with CPB. Temporary pacing electrodes were placed on the right atrium, apex of the right ventricle, and lateral wall of the LV after separation from CPB. The hemodynamic effects of three atrio-ventricular (right, left, and BiV) pacing modes were studied for four minutes each. The pacing sequence was randomly allocated with a resting period of three minutes between each mode. Hemodynamic and echocardiographic data of LV function were collected. Statistical analysis was performed with analysis of variance. RESULTS: BiV pacing increased cardiac output by 4%, 13%, and 44% over right ventricular pacing, LV pacing, and pre-bypass values, respectively. The fractional area of change increased significantly with BiV pacing compared to right ventricular and LV pacing (36%, 35% to 44%, p < 0.01). An increased propagation velocity of 49 cm/s compared to 38 cm/s and 40 cm/s for right ventricular and LV pacing, respectively, suggested an improvement in diastolic function. CONCLUSION: In patients with low EF, BiV pacing immediately after CPB significantly improves LV systolic function and cardiac output, and suggests significantly improved diastolic function.