Transtelephonic Electrocardiographic Monitoring Research Articles

GW24-e0319 The clinical significance of the automatic warning function of cardiac remote monitoring systems in preventing acute cardiac episodes

ObjectivesIn addition to ambulatory Holter electrocardiographic recording and transtelephonic electrocardiographic monitoring (TTM), a cardiac remote monitoring system can provide an automatic warning function through the general packet radio service (GPRS)...

Telemonitoring in Heart Failure Rehabilitation

Exercise training (ET) is now recommended as an important component of a comprehensive approach to patients with heart failure (HF). Despite the existence of proven benefits of ET, many HF patients remain physically inactive. Introducing telerehabilitation (TR) may eliminate most of the factors that result in the currently low number of patients undergoing outpatient-based rehabilitation programmes and thus increase the percentage of those who will undergo cardiac rehabilitation. Despite the fact that TR is highly applicable and effective, there are few papers dedicated to the study of TR in HF patients. Until recently, only a couple of home rehabilitation-monitoring models have been presented, from the simplest, i.e. heart rate monitoring and transtelephonic electrocardiographic monitoring, through to the more advanced tele-electocardiogram (tele-ECG) monitoring (via a remote device) and realtime electrocardiographic and voice transtelephonic monitoring. It seems the last two are the most useful and reliable. Based on published studies, TR in HF patients could be equally effective as and provide similar improvements in health-related quality of life to standard outpatient cardiac rehabilitation. In addition, adherence to cardiac rehabilitation seems to be better during TR. Due to disease-related limitations, TR seems to be a viable alternative for comprehensive cardiac rehabilitation in HF patients. Further studies are needed to confirm the utility of this type of rehabilitation in routine clinical practice, including its cost-effectiveness. Because of the diversity of technological systems, it is necessary to create a platform to ensure compatibility between the devices used in telemedicine.

Transtelephonic electrocardiographic monitoring of an outpatient cardiac rehabilitation programme

Objective: To address whether transtelephonic electrocardiographic monitoring (TEM) of patients with chronic cardiac diseases, being exercised in public gyms, is safe and efficacious. Design: Data were obtained from 91 patients (72 men and 19 women; with a mean (SD) age of 56 (6) years and over a total of 11 820 exercise hours) with coronary heart disease and/or chronic heart failure (≤ stage III NYHA (New York Heart Association)), who were referred for cardiac exercise rehabilitation (phase III). Method: Twelve-lead electrocardiograms of indicated patients were transmitted from the qualified trainers in real time by standard telephone lines and were evaluated by the medical staff at the base. The TEM kits contain a telemedicine 12-lead electrocardiographic unit, a telephone modem, a computer receiver with special operating software and a laser printer. As soon as the ECG was monitored and diagnosed, the cardiologist contacted the exercise trainer and provided all the necessary instructions for intervention. Results: In total, 280 cases were monitored. Successful TEM was reported in 99.3% of the cases. The mean (SD) time from ECG recordings to final interventions was estimated at 294 (13) s. The patients were referred for TEM during or soon after exercise sessions, because of chest pain (36% of the TEM cases), palpitations (33%), dizziness (12%), unexpected fatigue (9%), hypertensive crises (7%) and other disorders (3%). Ischaemic ECG changes were recorded in 14 cases with thoracic pain and arrhythmias in nine patients with palpitations. In only one case was a medical emergency reported and an ambulance response required. Conclusion: These data demonstrate that TEM provides a workable facility in cardiac rehabilitation for monitoring patients who are exercising in gyms.

Targeted pharmacological reversal of electrical remodeling after cardioversion—Rationale and design of the Flecainide Short-Long (Flec-SL) trial

Persistent atrial fibrillation (AF) causes relevant mortality and cardiovascular and noncardiovascular morbidity. Therefore, maintenance of sinus rhythm is an important clinical goal, especially when the patient is symptomatic, despite the fact that current treatment strategies are not sufficient to completely prevent recurrent AF. In addition to underlying atrial disease that predisposes to AF, AF in itself induces structural and electrical adaptations ("electrical remodeling" and "structural remodeling"). Underlying disease processes and parts of structural remodeling are not always reversible. Electrical remodeling, in contrast, is reversed by a few weeks of maintenance of sinus rhythm under experimental conditions. This corresponds to the period when most of the recurrent episodes of AF occur after cardioversion. Antiarrhythmic drugs that prolong the atrial action potential can assist in the prevention of recurrent AF by promoting the reversal of electrical remodeling. Such drugs, which are currently used over long periods after cardioversion, may only be needed until the physiological action potential duration is restored, for example, during the first few weeks after cardioversion of persistent AF. This treatment concept that we call "targeted pharmacological reversal of electrical remodeling" would limit both cost and drug-induced side effects of antiarrhythmic drug therapy after cardioversion. The Flec-SL trial, ISECTN62728743, therefore tests the main hypothesis that targeted pharmacological reversal of electrical remodeling by short-term antiarrhythmic drug therapy for 4 weeks after cardioversion is not inferior to standard long-term antiarrhythmic drug therapy for the prevention of recurrent AF after cardioversion in a parallel group, randomized, multicenter, open, blinded end point analysis design. Based on its effectiveness and pharmacokinetic profile, flecainide is used to test the study hypothesis. The trial uses daily transtelephonic electrocardiographic monitoring for all patients and will be conducted within the German Atrial Fibrillation Competence NETwork (AFNET) to facilitate inclusion of patients from electrophysiologically oriented cardiology centers, ordinary hospitals, and office-based physicians.

Role of Transtelephonic Electrocardiographic Monitoring in Detecting Short-Term Arrhythmia Recurrences After Radiofrequency Ablation in Patients With Atrial Fibrillation

Role of Transtelephonic Electrocardiographic Monitoring in Detecting Short-Term Arrhythmia Recurrences After Radiofrequency Ablation in Patients With Atrial Fibrillation

Role of transtelephonic electrocardiographic monitoring in detecting short-term arrhythmia recurrences after radiofrequency ablation in patients with atrial fibrillation

The aim of our study was to determine the incidence of asymptomatic recurrences of atrial fibrillation (AF) by daily transtelephonic (TT) electrocardiographic (ECG) monitoring, as compared with standard ECG and 24-h Holter recording, in patients who underwent radiofrequency catheter ablation (RCA) of AF. The efficacy of RCA of AF is usually evaluated by means of patients' symptoms. Seventy-two patients with paroxysmal (n = 37) or persistent (n = 35) drug-refractory AF underwent circumferential RCA of the pulmonary vein (PV) ostia. Left isthmus ablation was performed in 57 patients, and cavotricuspid isthmus ablation was done in 69 patients. Patients were scheduled to obtain an ECG and Holter recordings one and four months after ablation, as well as a daily TT ECG, from 30 to 120 days after ablation or in the event of symptoms. A total of 5,585 TT ECGs were obtained (mean 77.5 per patient). In 20 patients (27.8%), AF recurrences were recorded during TT ECG, whereas ECG and Holter monitoring revealed AF recurrences in 10 patients (13.9%, p = 0.001). Ten patients had at least one asymptomatic AF recurrence, and eight were completely asymptomatic. The ECG recorded in the event of symptoms always showed AF. Transtelephonic ECG is better than standard ECG and 24-h Holter recordings in evaluating AF relapses after RCA, thus decreasing the short-term success of ablation from 86% to 72%. The absence of symptoms should not be interpreted as absence of AF, as 50% of patients were asymptomatic during at least one AF episode.

Inpatient versus outpatient antiarrhythmic drug initiation: safety and cost-effectiveness issues.

Debate exists as to the proper site for initiating antiarrhythmic therapy for supraventricular tachyarrhythmias and other benign forms of ectopy: inpatient versus outpatient. Rapid detection of efficacy and adverse effects, with immediate correction of the latter, favors the inpatient site. Convenience and, under most circumstances, lower cost favor the outpatient site. Circumstances under which adverse event rates, including proarrhythmia, are expectedly low, would favor outpatient initiation. So would the use of an agent whose elimination half-life is so long as to render in-hospital monitoring to steady state highly impractical. Accordingly, outpatient initiation would be suitable for patients without structural heart disease receiving class IC drugs, patients with low risk for torsades de pointes receiving selected class III agents, in whom data in the literature are supportive (as has occurred with sotalol and azimilide), and patients who are to receive amiodarone. Transtelephonic electrocardiographic monitoring can be used to facilitate assessment in the outpatient setting. Inpatient initiation should be considered for patients with underlying sinus node or atrioventricular conduction disturbances, for patients with significant structural heart disease, for patients receiving a drug whose proarrhythmia may be idiosyncratic (e.g., quinidine), and for patients who are to begin an antiarrhythmic drug while in a supraventricular tachyarrhythmia in whom sinus rhythm has not previously been seen. The relative costs and benefits of the approach chosen will be a reflection of the probability that a drug with a chosen mechanism will cause an adverse outcome in a patient with a specific clinical substrate during the period chosen for monitoring.

Maintenance of sinus rhythm with oral d,l-sotalol therapy in patients with symptomatic atrial fibrillation and/or atrial flutter

Currently d,l-sotalol is widely used to prevent recurrence of atrial fibrillation and/or atrial flutter, although a randomized dose-response study has not previously been conducted to guide therapy for this indication. This study summarizes findings of a double-blind, placebo-controlled, multicenter, randomized trial evaluating the efficacy, safety, and dose-response relation of 3 fixed doses of d,l-sotalol (80, 120, and 160 mg twice daily) for the maintenance of sinus rhythm in 253 patients with atrial fibrillation and/or atrial flutter. All patients were in sinus rhythm at randomization. Treatment (69 patients on placebo, 59 on 80 mg, 63 on 120 mg, and 62 on 160 mg given twice daily) was continued for 12 months or until documented recurrence of symptomatic atrial fibrillation and/or flutter. Transtelephonic electrocardiographic monitoring was used to detect symptomatic recurrences. Demographic characteristics were not different in the 4 groups. Structural heart disease was present in 57% of patients. Patients with a history of heart failure were excluded. The time from randomization to symptomatic arrhythmia recurrence was significantly longer in the 2 higher d,l-sotalol dose groups than in the placebo group. The median times to recurrence were 27, 106, 229, and 175 days for the placebo, 80, 120, and 160 mg groups, respectively. There were no deaths or cases of torsade de pointes, sustained ventricular tachycardia, or ventricular fibrillation reported. Thus, d,l-sotalol appeared to be both safe and effective in maintaining sinus rhythm in patients with symptomatic atrial fibrillation and/or flutter. Further, the 120-mg twice daily dose appeared to provide the most favorable benefit and/or risk.

Trans-telephonic electrocardiographic monitoring--experience in India.

A centre for trans-telephonic electrocardiographic monitoring (TTEM) was established at the Escorts Heart Institute in May 1996. We have reviewed our experience in the first 398 patients. There were 321 males (81%) and 77 females (19%); their age range was 1 month to 95 years. Sixty-five per cent of patients were from New Delhi, while the remainder were from other cities in India and abroad. As well as follow-up of patients after discharge, the system was used for the evaluation of chest pain, palpitation, chronic angina, arrhythmias, and pacemaker implants. Out of 664 symptomatic transmissions, 510 (77%) were for cardiac symptoms like chest pain (309), palpitation (90), uneasiness (61), dizziness (28) and breathlessness (22); the other 154 (23) were for non-cardiac symptoms like stitch pain and backache (51), typical chest pain (39), weakness and fever (45), and sweating (19). The majority of patients with chest pain (84%), palpitation (78%) and dizziness (75%) transmitted their electrocardiograms within one hour of the onset of the symptoms. Out of 664 symptomatic transmissions, 531 required either reassurance or drug-dose adjustment by telephone and 97 were called to the outpatient department on an elective basis. Immediate hospitalization was advised for 36 patients, for acute management of their symptoms. TTEM was useful in avoiding 628 unnecessary visits to the hospital, while 36 patients were immediately hospitalized for acute care.

Incidence of symptomatic atrial fibrillation in patients with paroxysmal supraventricular tachycardia

This study was performed to determine the incidence of symptomatic, sustained atrial fibrillation in a group of patients with paroxysmal supraventricular tachycardia. The effects of the mechanism of paroxysmal supraventricular tachycardia (atrioventricular [AV] node reentry vs. AV reentry through an accessory pathway) and heart rate during the tachycardia on the occurrence of atrial fibrillation were also assessed. There is a substantial incidence of atrial fibrillation in patients with paroxysmal supraventricular tachycardia, but the precise incidence and the factors that determine it are unknown. One hundred sixty-nine patients with paroxysmal supraventricular tachycardia were followed up by regular clinic visits and transtelephonic electrocardiographic monitoring during symptomatic episodes of arrhythmia. The Kaplan-Meier product-limit method was used to estimate the proportion of patients remaining free of atrial fibrillation during the observation period. The Cox proportional hazards model was used to assess the effect of mechanism and heart rate during paroxysmal supraventricular tachycardia on the atrial fibrillation-free period. Thirty-two (19%) of the 169 patients had an episode of atrial fibrillation during a mean follow-up period of 31 months. The cumulative percent of patients experiencing an episode of atrial fibrillation was 6% within 1 month, 9% within 4 months and 12% within 1 year. The mechanism of paroxysmal supraventricular tachycardia was not associated with the time to occurrence of atrial fibrillation; the hazard ratio corresponding to classification in the AV node reentry group was 0.8 (p > 0.6). The heart rate during paroxysmal supraventricular tachycardia was not associated with the time to occurrence of atrial fibrillation; the hazard ratio associated with an increase in heart rate of 50 beats/min during the tachycardia was 1.15 (p > 0.5). This study suggests that atrial fibrillation will develop in approximately 12% of patients with paroxysmal supraventricular tachycardia during a 1-year follow-up period. The occurrence of atrial fibrillation is not related to the mechanism or heart rate of the paroxysmal supraventricular tachycardia.

Permanent pacing in children: Acute lead implantation and long-term follow-up

Optimal pacing in children mandates the proper selection of the pacing electrode system and appropriate follow-up testing. This review discusses factors that influence electrode selection, acute and chronic thresholds to be expected from each electrode type, electrode longevity in the child, and appropriate follow-up techniques applicable to the pediatric patient. Much information in this article is drawn from the Midwest Pediatric Pacemaker Registry. Epicardial electrode implantation has been the classic mode of electrode implantation used in children, but the endocardial approach has been increasingly used. At the current time, epicardial electrodes account for ~60% of electrodes implanted in children. Factors that require use of epicardial over endocardial pacing are small size of the patient, lack of venous access to the ventricle, the presence of right-to-left intracardiac shunting with risk of systemic embolization, and/or clotting abnormalities with an increased risk of large pulmonary emboli or the development of vena caval obstruction. The minimum size of the child deemed appropriate for endocardial pacing is controversial. Smaller electrode and generator size have decreased the lower age and weight at which endocardial implantation can be performed. However, the long-term consequences of long-term endocardial pacing in children is unknown. The most common source of epicardial electrode malfunction is electrode fracture, and the average longevity is 8.3 years. Long-term endocardial electrode failure is due predominantly to electrode fracture, with an average longevity >9 years. Finally, follow-up techniques are critical to ensure continued appropriate pacemaker system function because the underlying electrophysiological state may change. Follow-up techniques include pacemaker interrogation and threshold testing at the time of pacemaker clinic visit, ambulatory electrocardiographic monitoring, transtelephonic electrocardiographic monitoring and exercise testing. All techniques need to be used to ensure appropriate pacemaker function and programming.

Utility of transtelephonic ECG monitoring in evaluating discharges from a third-generation implantable cardioverter defibrillator

The authors report the case of a 60-year-old man with a third-generation implantable cardioverter defibrillator whose rate-sensing lead malfunction was diagnosed only after surface loop electrocardiographic (ECG) monitor recording. The stored R-R intervals suggested an irregular ventricular rhythm, but the loop ECG monitor demonstrated inappropriate shocks delivered during sinus rhythm.

Transtelephonic electrocardiographic monitoring of cardiac rehabilitation exercise sessions in coronary artery disease

Transtelephonic monitoring of a single-lead electrocardiogram and on-demand 2-way voice communication were accomplished at 1,865 exercise sessions for 67 cardiac patients. Exercise sessions occurred either at the patients' homes or at remote hospital sites and began an average of 25 or 14 weeks, respectively, after hospital dismissal. Monitoring centers provided experienced nurses to direct all exercise sessions. The transtetephonic monitoring equipment was reliable with only one instance of system failure observed. A broad spectrum of patients with coronary artery disease, including some classified at higher risk, participated in the program. Patients exercised with a variety of equipment (cycle ergometer, treadmill, arm ergometer, cross-country ski simulator, combination arm-leg cycle ergometer, rowing machine), for 30 to 50 minutes, 1 to 3 times each week. No medical emergencies occurred, although 18 specific problems were discovered that led to further evaluation or change in the medical program of specific patients. Transtelephonic monitoring of cardiac rehabilitation exercise sessions at home and at remote hospitals appears safe and is attractive because not all patients have access to supervised exercise programs; this exercise assessment helps to maximally use highly trained cardiac rehabilitation personnel.

Optimum duration of transtelephonic ECG monitoring when used for transient symptomatic event detection

Transtelephonic electrocardiographic monitoring (TTM) has been used for postpacemaker follow-up study, postmyocardial infarction monitoring, and transient symptomatic event detection (TSED). For postpacemaker follow-up study, TTM is continued indefinitely. For postmyocardial infarction monitoring, TTM is continued for 1 year or more. For TSED, the appropriate duration for TTM has not yet been adequately assessed. Accordingly, the authors determined the yield, by week, of TTM for TSED. Five thousand fifty-two patients who made 20,590 calls were analyzed for this investigation. Ninety-five percent of patients making symptomatic calls or making a call in which an arrhythmia was documented did so within 5 weeks. Shorter periods would sacrifice yield, longer periods may not be cost-effective.

Detecting Arrhythmia by Exercise Electrocardiography in Pediatric Patients: Assessment of Sensitivity and Influence on Clinical Management

We studied 49 patients with suspected arrhythmias (group 1) and 92 patients with previously documented arrhythmias (group 2) who underwent exercise electrocardiography (EECG) at our institution between 1979 and 1987. Among group 1 patients, all of whom had sinus rhythm before exercise, 10 (20%) had abnormal findings on EECG, and treatment was modified in 4 of these 10 (8% of group 1). Further testing (24-hour ambulatory or transtelephonic electrocardiographic monitoring or electrophysiologic study) of the 39 patients with normal EECG findings revealed 8 additional patients with arrhythmias. In group 1, the sensitivity of EECG was 56%, and its negative predictive value was 79%. Group 2 consisted of 38 patients with atrial arrhythmias, 31 with ventricular arrhythmias, and 23 with atrioventricular conduction abnormalities before EECG. Of these 92 patients, 68 (74%) had abnormal EECG findings. All but 1 of the 24 patients with normal findings underwent further testing, and rhythm abnormalities were induced in 16. Patients with atrial arrhythmias were more likely to have normal EECG results (42%) than were those with ventricular arrhythmias (23%) or an atrioventricular conduction abnormality (4%). Of the 35 patients who had been referred for suppression of an arrhythmia, 25 (71%) had abnormal rhythm suppressed during exercise. Clinical management was modified in 27% of group 2 patients on the basis of EECG findings.

Transtelephonic electrocardiographic monitoring for detection and treatment of cardiac arrhythmia

Published data on the use of transtelephonic electrocardiographic monitoring for evaluation of episodic symptoms suggestive of cardiac arrhythmia are sparse and conflicting. We have reviewed the use of one such device 'Cardiomemo' on our unit over an 18 month period. The study showed that transtelephonic electrocardiographic monitoring is useful in documentation of infrequent or sporadic episodes directly related to symptoms when 24-hour ambulatory electrocardiograph monitoring is normal.

Efficacy of Transtelephonic Electrocardiographic Monitoring in Pediatric Patients

The results of transtelephonic electrocardiography for transient symptomatic event recording in 61 consecutive pediatric patients (aged 4 months to 21 years) were reviewed. In 13 (21%) of 61 patients, previous arrhythmia diagnoses had been made by electrophysiologic study; monitoring was utilized to evaluate symptoms before or after pharmacological/surgical therapy. Transtelephonic electrocardiography was used to study undocumented symptomatic events consistent with an arrhythmia in the remaining 48 (79%) of 61 patients. Adequate transmissions during symptoms were obtained in 36 (59%) of 61 patients. Goals of monitoring were achieved in all 13 patients with previous diagnoses. Of the 25 of 48 patients without prior diagnoses who provided transmissions during symptoms, 15 had sinus rhythm, while 10 manifested an arrhythmia. Abnormal transmissions were most common in patients with palpitations and never evident in patients with symptoms of chest pain.

Transtelephonic electrocardiographic monitoring: Reliability in detecting the ischemic ST segment response during exercise

The ECG detection of ST segment depression during maximal treadmill exercise has diagnostic and prognostic significance in coronary artery disease. This study of 200 consecutive patients undergoing Bruce exercise testing for chest pain documents the ability of a transtelephonic ECG system, capable of storing segments of ECG memory during exercise, to reliably record ST segment depression detected during simultaneous exercise testing (sensitivity 79%; specificity 99.6%). Of the three transtelephonic ECG systems tested, the modified precordial V 5 snap-on lead most accurately reflected ST segment amplitude and morphology with no “false positives” (specificity 100%) and few “false negatives” (sensitivity 78%). Therefore, this system is a potentially important clinical tool for accurately and conveniently monitoring coronary patients during exercise outside the hospital (e.g., following myocardial infarction) as well as for providing useful clinical information for ambulatory patients with undiagnosed sporadic chest pain.

The 1981 United States survey of cardiac pacing practices

A survey of physicians implanting pacemakers was conducted to obtain a profile of permanent cardiac pacing practices in the United States during 1981. Questionnaires were mailed to 5,832 implanters with 765 responses (13%) received and 680 analyzed. It was estimated that there were approximately 5,600 physicians, 66% surgeons and 34% nonsurgeons, implanting pacemakers at 3,670 centers. About 118,000 new primary implants were performed, or 518 per million population. Only 17% of implantation procedures in 1981 were replacements compared with 31% in 1978. Roughly half the respondents worked in teams, most implanting from 46 to 55 pacemakers annually. The chief indications for permanent pacing were sick sinus syndrome (48%) and impairment of conduction in the atrioventricular node and His-Purkinje system (42%). Ninety-five percent of pacing leads were implanted transvenously. Seventy percent of the respondents had had experience with atrial and dual-chamber pacemakers, used largely to increase cardiac output. The use of ventricular demand (VVI) pacing decreased accordingly from 91% in 1975 to 84% in 1981. Although approximately 90% of primary pacemakers were programmable to some degree, almost half were not reprogrammed within the first 3 months after implantation and 30% were never reprogrammed. Most patients (85%) were followed up by transtelephonic electrocardiographic monitoring, 68% in conjunction with private office visits. The respondents estimated that dual-chamber pacing, accounting for 10% of implants in 1981, would increase to 37% by 1985. Early electrode malfunctions were less frequent when implantation was performed by high volume and solo implanters, and in public and community hospitals. It is concluded that periodic surveys of this type disclose important trends in the practice of cardiac pacing.

Long-term transtelephonic electrocardiographic monitoring in the detection and evaluation of variant angina

To facilitate the outpatient diagnosis of variant angina by documenting transient ST segment evaluation during chest pain, we studied the feasibility of transtelephonic ECG monitoring during angina episodes. Eight patients with known coronary artery spasm underwent simultaneous continuous ambulatory and transtelephonic ECG monitoring during a 24-hour period. Five patients (62%) had transient diagnostic ST segment shifts on both continuous ambulatory and transtelephonic monitoring. Another eight patients with coronary spasm underwent 24-hour continuous ambulatory monitoring and separate 14-day period of transtelephonic monitoring. The addition of this longer monitoring period provided diagnostic ST segment shifts in three patients. We conclude that transtelephonic monitoring in patients with suspected coronary artery spasm can provide important additional diagnostic information to continuous ambulatory monitoring, particularly in the patient with infrequent or predictable chest pain.