Cardiac Pacemaker Insertion Research Articles

Cardiovascular Abnormalities and Arrhythmias in Patients with Ondine's Curse (Congenital Central Hypoventilation) Syndrome

Patients with congenital central hypoventilation syndrome (CCHS) (Ondine's curse syndrome) have impaired autonomic control of ventilation with intact voluntary control of respiration. Autonomic dysfunction and cardiac abnormalities are common in CCHS. Bradyarrhythmias are life-threatening and often require pacemaker insertion. We presented a case of a patient with CCHS suffering from long sinus pauses requiring cardiac pacemaker insertion. Patients with CCHS are at risk for pulmonary hypertension and cor pulmonale secondary to chronic hypoxia. Diaphragmatic pacing has been beneficial in some patients with CCHS. In this article, we review concomitant cardiac abnormalities and the occurrence of bradyarrhythmias in patients with CCHS.

Reevaluation of temporary transvenous cardiac pacemaker usage during carotid angioplasty and stenting: a safe and valuable adjunct.

Although many current series document the safety of carotid angioplasty and stenting procedures (CAS), several acknowledge clinically significant hemodynamic disturbances in 25-71% of patients. We report herein the safety and efficacy of prophylactic percutaneous temporary transvenous cardiac pacemaker insertion during CAS for the prevention of hemodynamic changes. At a community-based institution, 48 patients undergoing 51 attempted CAS procedures from March 1999 to August 2002 for carotid artery occlusive disease were retrospectively reviewed. Thirty-one percent of patients had procedures performed for either recurrent disease or a history of neck radiation; 62.5% had significant coronary disease. Temporary transvenous pacemakers were inserted as an adjunctive procedure in the authors' CAS protocol. The pacers were set to capture a heart rate decrease below 60 beats per minute. Demographics, cardiac risk, and outcomes were analyzed. CAS was successfully performed in 96% (49 lesions). In the intent-to-treat group, the patients had a mean age of 71 +/-9 years and angiographic stenoses of 88 +/-8%, with 29% having symptomatic lesions. Significant bradycardia or asystole to trigger ventricular pacing occurred in 11 (22%) procedures, thus, triggering ventricular pacing. Pharmacologic support for concomitant hypotension was temporarily necessary in only 4 (8%) cases. No patient required prolonged pacing or medication therapy following CAS. Neither presence of carotid-related symptoms nor disease etiology was related to need for intraprocedural pacing. Furthermore, there was no occurrence of pacemaker failure or other complication secondary to venous catheterization. Hemodynamic changes may occur during mechanical dilation of the carotid artery and bulb, with reports in the literature of the need for prolonged pharmacologic support. In selected patients, the prophylactic placement of a transvenous pacemaker is a safe, feasible, and expeditious method to treat periprocedural hemodynamic changes with a decrease in additional pharmacologic support during CAS.

Prevalance of diabetes in elderly patients requiring permanent cardiac pacemaker insertion

Diabetes mellitus increases the rate of atrioventricular block after a myocardial infarction; right bundle branch block is more common than expected in the diabetic outpatient population. We decided to assess whether diabetic subjects were more likely to need permanent cardiac pacemaker insertion. Data from patients in Leicestershire who had undergone permanent cardiac pacemaker insertion during a 4-year period were analysed. The capture recapture technique was used: Hospital Activity Analysis data as capture, ward admission book and case note confirmation as recapture. Diabetes coding accuracy was confirmed from the central register and from an analysis of 100 sets of case notes. The number of these patients with diabetes was then recorded. Data for the reference population was obtained using a survey of a market town in Leicestershire. There were 688 patients, most (79%) aged over 65 years. Our analysis was performed on this group. Of this age group undergoing pacemaker insertion. 11.1% was diabetic. In the same age group, 8.3% of the controls were diabetic: a relative risk of 1.34 (P < 0.01, 95% confidence interval 1.25-1.44). This relative risk is likely to be an underestimate. The aetiology of this excess risk is uncertain: it is most likely due to ischaemic heart disease, but microangiopathy or increased cholinergic sensitivity may play a role.

978-63 The Value of Exercise Testing for Predicting the Outcome in Patients with Congenital Third Degree A-V Block

Ambulatory monitoring (AM) has been reported to have important prognostic value in patients with third degree congenital heart block (CHB). The purpose of this study was to compare clinical, electrocardiographic, exercise (Ex), and ambulatory monitoring variables in predicting outcome in patients with CHB. Multiple clinical (age, gender, race, associated congenital defects, symptoms), and electrocardiographic variables (rest heart rate [HR], QRS duration, atrial rate, resting arrhythmias) were analyzed for 40 patients with CHB but without a pacemaker. Exercise treadmill testing was performed in 17 patients and ambulatory monitoring in 21 patients. Events were defined as cardiac death (n = 2) and/or pacemaker insertion (n = 27). The median follow-up interval was 8 years. No clinical or rest electrocardiographic variables were associated with subsequent events, although there was a trend for the presence of symptoms and low resting HR (p = 0.07 for both). In contrast to ambulatory monitoring, exercise testing was significantly associated with events:Empty CellEventsNo EventsPEx Variables Peak HR99 ± 24135 ± 320.03 (Peak-rest) HR47 ± 2167 ± 170.18 Rate-pressure product16,100 ± 567023,450 ± 16400.03AM variables Average HR51 ± 1258 ± 17NS Minimum HR38 ± 545 ± 120.09 Maximum HR83 ± 2477 ± 17NS Clinical and rest electrocardiographic variables, by themselves, are not helpful in predicting outcome in pts with CHB. The addition of exercise testing is more closely associated with outcome than ambulatory monitoring in patients with CHB.

A complete regional anesthesia technique for cardiac pacemaker insertion

Sixteen consecutive adult patients scheduled for permanent transvenous cardiac pacemaker insertion received as their total anesthetic the combination of a cervical plexus block and blocks of the second, third, and fourth intercostal nerves using a combination of 1% mepivacaine and 0.2% tetracaine with epinephrine, 1:200,000. This technique consistently provided complete surgical anesthesia of the third cervical (C 3) through the fourth thoracic (T 4) dermatomes, without anesthesia of the brachial plexus. Anesthesia was adequate for the surgical procedure without the need for supplemental analgesia or anesthesia in all cases. Because fluoroscopy was used routinely for the surgical procedure, it was possible to document that there were no instances of diaphragmatic paralysis or pneumothorax. In contrast to other reports, this technique provides surgical anesthesia that is adequate for all of the approaches used for transvenous pacemaker implantation, except for placement of a battery in an abdominal pouch. There were no serious complications and/or side effects in any of the patients studied.

Perspective on Surgical Indications Implications for Controls

Surgical indications do not forecast outcomes as well as they should. A review of the literature demonstrates a significant rate of overutilization of coronary angiography, coronary artery surgery, cardiac pacemaker insertion, upper gastrointestinal endoscopies, carotid endarterectomies, back surgery, and pain-relieving procedures. The tendency appears to be a reduction in developing specific indications, and the evolution of a "last resort" concept. Arguments against this approach and a plea for the development of tighter focused indications are presented. Implications for cost saving and reduction in suffering are discussed.

Regional anesthesia for pacemaker insertion.

Four local or regional anesthesia techniques for the insertion of cardiac pacemaker were studied prospectively in 40 patients. The four techniques studied were: local anesthesia, field block of the supraclavicular nerves, interscalene block at C4, and interscalene block at C6. The three goals of the study were to find the technique that gave the best quality of analgesia, the incidence of complications related to each technique, and the area of sensory innervation of C4. No technique was found to be superior to the others with regard to the quality of analgesia. Interscalene blocks at C4 and C6 were associated with complications and side effects more often than the two other techniques. The authors also suggest that the dermatome of C4 is not under the clavicle but above the clavicle. It was concluded that local anesthesia infiltration at the site of cardiac pacemaker insertion or field block of the supraclavicular nerves are the best techniques for cardiac pacemaker insertion.

Thioridazine-induced torsade de pointes. Successful therapy with isoproterenol

Thioridazine (Mellaril) hydrochloride cardiotoxicity is manifested by bradycardia and prolongation of the QT interval. The latter predisposes to atypical ventricular tachycardia (torsade de pointes) when premature ventricular depolarizations occur during the prolonged QT interval. Isoproterenol hydrochloride infusion, which increases the heart rate and shortens the QT interval, is a theoretically advantageous therapeutic modality for use in this situation. This report describes a case of thioridazine-induced torsade de pointes that was successfully managed with isoproterenol infusion after therapy with other agents was unsuccessful. This mode of therapy should be used with caution, but it may be lifesaving in psychiatric or community hospitals where temporary cardiac pacemaker insertion is not performed. (JAMA1983;249:2931-2934)

Thioridazine-Induced Torsade de Pointes

Thioridazine (Mellaril) hydrochloride cardiotoxicity is manifested by bradycardia and prolongation of the QT interval. The latter predisposes to atypical ventricular tachycardia (torsade de pointes) when premature ventricular depolarizations occur during the prolonged QT interval. Isoproterenol hydrochloride infusion, which increases the heart rate and shortens the QT interval, is a theoretically advantageous therapeutic modality for use in this situation. This report describes a case of thioridazine-induced torsade de pointes that was successfully managed with isoproterenol infusion after therapy with other agents was unsuccessful. This mode of therapy should be used with caution, but it may be lifesaving in psychiatric or community hospitals where temporary cardiac pacemaker insertion is not performed.

Cardiac pacemaker insertion: A study of the anaesthetic and postoperative complications

One hundred and three patients undergoing pacing procedures have been studied, the majority requiring the insertion of an epicardial system under general anaesthesia. The main findings were of an elderly group of patients with a high incidence of associated disease, who suffered predominantly from pulmonary and renal complications. Methods of reducing these complications, particularly in relation to general anaesthesia are discussed.

His bundle recordings in patients with bundle branch block and transient neurologic symptoms.

His bundle electrograms were recorded in 19 patients with bundle branch block (BBB) and transient neurologic symptoms allowing for determination of intra-atrial (P-A), atrioventricular (A-V), nodal (A-H) as well as infranodal conduction (H-Q) times. The patients were initially monitored in a coronary care unit and have been followed for a mean period of 8 ± 4 months. In six patients (Group I) neurologic symptoms were observed in the absence of electrocardiographic evidence of A-V block. In six patients (Group II) the cause of symptoms was uncertain; two of these patients had relief of symptoms after permanent cardiac pacemaker insertion and were presumed to have episodic high grade A-V block. In seven subjects (Group III) complete A-V block was documented as the cause of the symptoms; these patients were studied when 1:1 antegrade A-V conduction returned. There was no significant difference between mean P-A, A-H, and QRS durations among the patients in the three groups. Mean H-Q (89 ± 20 msec) for Group III was significantly longer than that for Group I (56 ± 9 msec) or Group 11 (64 ± 11 msec) ( P &lt; .001). All patients with presumed or documented episodes of high grade A-V block had abnormal H-Q intervals, and six of the nine patients with presumed or documented complete A-V block had H-Q intervals &gt;80 msec. The present data suggest that patients with transient neurologic symptoms, bifascicular or left BBB associated with marked prolongation of H-Q (≧80 msec), should be seriously considered as candidates for insertion of a permanent cardiac pacemaker even in the absence of documented high grade or completeA-V block.

Cardiovascular responses to hypertonic glucose. An aspect of resuscitation studied in patients with chronic renal failure.

Cardiovascular responses to hypertonic glucose. An aspect of resuscitation studied in patients with chronic renal failure.