Value of Holter monitoring in assessing cardiac arrhythmias in symptomatic patients

The Role of Electrocardiographic Exercise Testing for the Possibility of Permanent Pacemaker Implantation in Patients with Sinus Bradycardia

Objective

Study on the role of electrocardiographic (ECG) exercise testing for the possibility of permanent pacemaker implantation (PPI) in patients with sinus bradycardia (SB).

Methods

Cross-sectional descriptive, prospective study. The study on 60 patients with SB below 50 beats/minute on 12-lead electrocardiogram at rest, with or without symptoms of SB, conducted at the Vietnam National Heart Institute and Hanoi Heart Hospital from January 2020 to September 2021.

Results

Sixty patients with SB were studied, 36 male (60%) and 24 female patients (40%), p > 0.05. The average age was 55.12 ± 13.89 years old. Maximum exercise capacity (MEC) is low and only reaches 7.78 ± 3.59 metabolic equivalents (METs); Not reaching 85% of predicted MEC accounts for 53.5%; Maximum exercise time is 10.53 ± 0.46 minutes; Impaired heart rate (HR) variability in patients with SB is high: Chronotropic Index <0.8 accounts for 53.5%, not reaching 85% of predicted HR max accounts for 45%. The average HR max was 129.90 ± 29.22 beats per minute (BPM). The average maximum workload systolic blood pressure was 155.23 ± 20.59 mmHg. The average value of maximum exercise diastolic blood pressure was 88.10 ± 9.11 mmHg. The HR decreased by 27.87 ± 16.82 BPM in the first minute. Not achieving 85% of predicted MEC (p = 0.062), so it is not an independent factor predicting the ability for PPI. Only the HR variability index <0.8 is an independent predictor for PPI in bradycardic patients, which has OR = 21.521 (95% CI: 2.27-04.34, p < 0.05).

Conclusion

Results can be seen that Chronotropic Index <0.8 is an important marker for physicians to decide on PPI in ECG during exercise testing in SB patients and is a potential prognostic factor for the need for PPI.

Tachy-brady syndrome: Electrophysiology and evolving principles of management

Sudden alterations in the heart rate may be associated with diverse symptoms. Sinus node dysfunction (SND), also known as sick sinus syndrome, is a sinoatrial (SA) node disorder. SND is primarily caused by the dysfunction of the pacemaker, as well as impaired impulse transmission resulting in a multitude of abnormalities in the heart rhythms, such as bradycardia-tachycardia, atrial bradyarrhythmias, and atrial tachyarrhythmias. The transition from bradycardia to tachycardia is generally referred to as "tachy-brady syndrome" (TBS). Although TBS is etiologically variable, the manifestations remain consistent throughout. Abnormal heart rhythms have the propensity to limit tissue perfusion resulting in palpitations, fatigue, lightheadedness, presyncope, and syncope. In this review, we examine the physiology of tachy-brady syndrome, the practical approach to its diagnosis and management, and the role of adenosine in treating SND.

Independent association of palpitation with vasomotor symptoms and anxiety in middle-aged women

OBJECTIVE

Palpitation, or the sensation of rapid or irregular heartbeats, is common in menopausal women; however, the precise underlying mechanisms are unknown. We aimed to investigate factors associated with palpitation in middle-aged women.

METHODS

Medical records of 394 women aged 40 to 59 years (108 premenopausal, 85 perimenopausal, and 201 postmenopausal) were analyzed cross-sectionally. Palpitation severity was estimated based on responses to the Menopausal Symptom Scale. Effects of background characteristics, including age, menopausal status, body composition, cardiovascular parameters, basal metabolism, physical fitness, lifestyle factors, vasomotor, and psychological symptoms on palpitation were assessed using multivariate logistic regression analysis. The association between autonomic nervous system activity and palpitation was also analyzed in 198 participants.

RESULTS

Prevalence of palpitation by severity was as follows: none, 26.4%; mild, 32.7%; moderate, 29.4%; severe, 11.4%. In univariate analyses, the more severely the women were affected by palpitation, 1) the higher their systolic blood pressure, 2) the less exercise they performed, 3) the lower they scored in the sit-and-reach test, 4) the higher their vasomotor symptoms score in the Menopausal Health Related-Quality of Life questionnaire, and 5) the higher their Hospital Anxiety and Depression Scale. Multiple logistic regression analysis revealed that moderate to severe palpitation was independently associated with the vasomotor symptom score (adjusted odds ratio [95% confidence interval]: 1.18 [1.07-1.31]) and Hospital Anxiety and Depression Scale anxiety subscale score (1.19 [1.12-1.27]).

CONCLUSIONS

Rapid or irregular heartbeats are highly prevalent in middle-aged women. It is not associated with age, menopausal status, heart rate, arrhythmia, autonomic nervous system activity, caffeine, or alcohol consumption, but with vasomotor symptoms and anxiety.

Supervised SVM Transfer Learning for Modality-Specific Artefact Detection in ECG

The electrocardiogram (ECG) is an important diagnostic tool for identifying cardiac problems. Nowadays, new ways to record ECG signals outside of the hospital are being investigated. A promising technique is capacitively coupled ECG (ccECG), which allows ECG signals to be recorded through insulating materials. However, as the ECG is no longer recorded in a controlled environment, this inevitably implies the presence of more artefacts. Artefact detection algorithms are used to detect and remove these. Typically, the training of a new algorithm requires a lot of ground truth data, which is costly to obtain. As many labelled contact ECG datasets exist, we could avoid the use of labelling new ccECG signals by making use of previous knowledge. Transfer learning can be used for this purpose. Here, we applied transfer learning to optimise the performance of an artefact detection model, trained on contact ECG, towards ccECG. We used ECG recordings from three different datasets, recorded with three recording devices. We showed that the accuracy of a contact-ECG classifier improved between 5 and 8% by means of transfer learning when tested on a ccECG dataset. Furthermore, we showed that only 20 segments of the ccECG dataset are sufficient to significantly increase the accuracy.

Autonomic Nervous System Response during Light Physical Activity in Adolescents with Anorexia Nervosa Measured by Wearable Devices

Anorexia nervosa (AN) is associated with a wide range of disturbances of the autonomic nervous system. The aim of the present study was to monitor the heart rate (HR) and the heart rate variability (HRV) during light physical activity in a group of adolescent girls with AN and in age-matched controls using a wearable, minimally obtrusive device. For the study, we enrolled a sample of 23 adolescents with AN and 17 controls. After performing a 12-lead electrocardiogram and echocardiography, we used a wearable device to record a one-lead electrocardiogram for 5 min at baseline for 5 min during light physical exercise (Task) and for 5 min during recovery. From the recording, we extracted HR and HRV indices. Among subjects with AN, the HR increased at task and decreased at recovery, whereas among controls it did not change between the test phases. HRV features showed a different trend between the two groups, with an increased low-to-high frequency ratio (LF/HF) in the AN group due to increased LF and decreased HF, differently from controls that, otherwise, slightly increased their standard deviation of NN intervals (SDNN) and the root mean square of successive differences (RMSSD). The response in the AN group during the task as compared to that of healthy adolescents suggests a possible sympathetic activation or parasympathetic withdrawal, differently from controls. This result could be related to the low energy availability associated to the excessive loss of fat and lean mass in subjects with AN, that could drive to autonomic imbalance even during light physical activity.

The diagnostic significance of the holter monitoring in the evaluation of palpitation

PURPOSE

To determine the diagnostic yield of the 24-hour Holter monitoring in the patients who were evaluated for palpitations.

METHODS

A prospective, single-centre study was performed to evaluate the diagnostic yield of the Holter monitoring. The inclusion criteria was age greater then 18 years with the symptom of unexplained recurrent palpitations. The exclusion criteria was patients with known medical causes of palpitation, a history of documented arrhythmias, or a history of or the current use of anti-arrhythmic drugs. The outcomes included a diagnostic Holter monitor recording.

RESULTS

The data analysis of the 335 patients who were studied, showed that there were 160 (47.8%) females and 175 (52.2%) males with a mean age of 55± 18.85 years (18 to 90 years). Ventricular ectopics as bigeminy in 36.7% patients and as couplets in 20% patients, were detected. Non-sustained VT was detected in 5.7% patients, VT was detected in 0.9% cases and SVT was detected in 12.5% cases. 3.58% cases had paraxosymal atrial flutter/fibrillation. The ST segment shift which is suggestive of silent ischaemia, was present in 17.6% of the study population. Second or higher degrees of AV blocks were noted in 2 cases, while one patient had the WPW syndrome. Ventricular bigeminy, couplets, VT,SVT and AF were statistically significant in the patients who were over the age of 50 years as compared to those who were less than 50 years.

CONCLUSION

In patients with non-specific symptoms, Holter monitoring has a significant role in the primary diagnosis of myocardial ischaemia or arrhythmia as a cause of such symptoms in the older age groups.

The clinical impact of long-term ECG recording. A retrospective study of 150 patients

One-hundred and fifty patients referred for long-term ECG (LECG) recording at a university hospital were monitored for 12 hours or more. The referring physicians' patient records were studied 12 months or more after monitoring in an attempt to establish if and how LECG had affected patient management. Seventeen patients were treated with permanent pacemakers and 13 with antiarrhythmic drugs as a direct result of LECG. Thirteen patients who experienced symptoms with concomitant cardiac arrhythmia at the time of recording were considered not to require treatment. In 17 patients who experienced symptoms without concomitant arrhythmia during monitoring, cardiac arrhythmia could be ruled out as the cause of the symptoms. In 9 more patients, LECG was considered to have contributed "valuable clinical information" (which could not be obtained by other diagnostic methods) to the referring physician. Thus, LECG was considered to have affected the referring physician's management of the patients in 69 cases (46%).

Relation between arrhythmic sensations, cardiac arrhythmias and psychological profile

The relation between arrhythmic sensations and objective findings of ectopic arrhythmic activity was studied in 150 middle-aged men. Objective arrhythmias were studied by 24-hour Holter monitoring and subjective symptoms assessed by a questionnaire and a dairy protocol during the ECG recording. Psychological characteristics were described by means of a personality inventory, the Emotions Profile Index. No direct relationship was found between subjective symptoms and objective findings of cardiac arrhythmias. Those men, however, who complained of arrhythmic sensations but had no clinically important arrhythmias exhibited a few specific characteristics. They had no signs of organic heart disease and appeared less trustful and more aggressive than those with arrhythmias.

Frequency and distribution of long-term ECG-recorded cardiac arrhythmias in an elderly population. With special reference to neurological symptoms

The prevalence of serious episodic cardiac arrhythmias known to correlate with cerebral symptoms was investigated in 103 elderly, randomly selected persons with the aid of 22 hours of long-term ECG recording (LTER). Twelve of 26 subjects with dizziness/syncope had serious episodic arrhythmias compared with 5 of 77 subjects without these symptoms. This difference is significant (p less than 0.001). Five patients fulfilled strict criteria for pacemaker treatment of symptomatic bradycardias. Three had the sick sinus syndrome and two had third degree atrioventricular block. In 4 subjects, drugs were withdrawn due to bradycardia; and 4 were treated for tachyarrhythmias. Despite the finding of minor arrhythmnias in almost all asymptomatic subjects, it is concluded that serious episodic arrhythmias in the elderly are related to cerebral symptoms. It is also concluded that these arrhythmias are more common than previously believed and that LTER should be widely used.

Episodic cardiac arrhythmia and accident rate

The rate of accidents severe enough to require a roentgen examination was investigated in a series of patients with episodic cardiac arrhythmia of types causing Adams-Stokes' syndrome. The accident rate was doubled compared with controls without known Adams-Stokes' syndrome but the associated increase in fracture rate was not significant.

Ambulatory ECG recording in patients referred because of syncope or dizziness

Data are presented on patients referred for ambulatory ECG recording because of syncope or dizziness during a 2-year period. Of the 272 consecutive patients subjected to the recording, 107 (39.3%) had syncope or dizziness as the main indication for referral. Sixteen of these patients (14.9%) experienced the presenting symptom during the recording, and in 8 (50%) of these the simultaneous ECG finding was interpreted as causative. In patients who were symptom-free during the recording, sinus arrests exceeding 2.5 seconds seemed to be a valuable finding to support the cardiac aetiology of the syncopal symptoms, whereas the diagnostic value of second degree AV block with either Wenckebach or Mobitz II like patterns, as such, and of ventricular tachycardia remained mostly unsettled.

Monitorização eletrocardiográfica ambulatorial por 24-horas em cães com cardiomiopatia dilatada idiopática

Caracterizou-se monitorização eletrocardiográfica ambulatorial por 24 horas (ou monitorização Holter) em cães com cardiomiopatia dilatada idiopática, visando principalmente à detecção de arritmias ventriculares não detectadas pela eletrocardiografia convencional (de repouso). Para tanto, avaliaram-se 40 pacientes com diagnóstico de cardiomiopatia dilatada idiopática, por meio de exame físico e mensuração indireta da pressão arterial, além de exames eletrocardiográfico, ecocardiográfico, radiográfico de tórax e da monitorização Holter. Extra-sístoles ventriculares foram detectadas, por monitorização Holter, em 97,5% dos animais e taquicardia ventricular, em 45%. Não houve correlação entre o número de extra-sístoles ventriculares e a fração de encurtamento. Considerando as manifestações clínicas, apenas houve associação entre presença de taquicardia ventricular e histórico de síncopes. Conclui-se que a incidência de arritmias ventriculares em cães com cardiomiopatia dilatada idiopática é bastante alta, sendo a taquicardia ventricular relativamente freqüente, ocorrendo mais sob a forma não sustentada.

Atrial fibrillation and falls in the elderly

Atrial fibrillation is an extremely rare cause of falls and syncope in the elderly. The routine use of ambulatory ECG monitoring to search for atrial fibrillation in elderly patients who fall is not recommended. Among elderly patients with atrial fibrillation who fall, short pauses of less than 3 seconds are nonspecific and are as common in patients who fall as they are in those who do not. Furthermore, most pauses are not associated with symptoms. Although the decision to implant a pacemaker for extremely long pauses is often straightforward, the decision to implant a pacemaker in patients who fall and who have short pauses ideally should be made after symptoms clearly have been associated with the dysrhythmia. This type of symptom-rhythm correlation is extremely valuable and often requires long-term ambulatory monitoring with external or internal (implanted) event or loop recorders. Among the growing population of elderly persons with chronic atrial fibrillation, oral anticoagulant therapy has been shown to have significant benefit and is underused, particularly in frail residents of long-term care facilities. The published literature does not support the commonly held belief that a patient's propensity to fall is an important factor in determining optimal antithrombotic therapy. Demographic shifts in the worldwide population continue to alter the practice of medicine, which is being influenced increasingly by the health care needs of the expanding elderly population. Additional research is needed to clarify the relationship between atrial fibrillation and falls in the elderly.

Comparison of in-hospital versus 24-hour ambulatory electrocardiography for detection of ventricular premature complexes in mature Boxers

OBJECTIVE

To evaluate the use of in-hospital electrocardiography (ECG) for detection of ventricular premature complexes (VPC), compared with 24-hour ambulatory ECG.

DESIGN

Original study.

ANIMALS

188 Boxers > 9 months old; 31 had a history of syncope, and 157 were healthy (no history of syncope).

PROCEDURE

In-hospital ECG was performed on all Boxers for at least 2 minutes. Within 7 days after the in-hospital ECG was completed, 24-hour ambulatory ECG was performed.

RESULTS

The specificity of in-hospital ECG was 100% for the detection of at least 50 VPC in a 24-hour period in dogs with syncope and 93% in healthy dogs. In-hospital ECG had poor sensitivity, although sensitivity increased as the number of VPC per 24 hours increased.

CONCLUSIONS AND CLINICAL RELEVANCE

Use of in-hospital ECG is highly specific for detection of at least 50 VPC during a 24-hour period. However, in-hospital ECG is insensitive, and a lack of VPC does not suggest that the dog does not have a substantial number of VPC during that same period. The use of in-hospital ECG appears to be inadequate for screening purposes and therapeutic evaluations in mature Boxers with ventricular arrhythmic disease.

Ambulatory electrocardiography for the detection of pacemaker lead failure

The suboptimal performance of some polyurethane bipolar pacing leads has highlighted concern about the optimal method of monitoring pacemaker lead performance. Since the manifestations of premature lead failure may be initially intermittent, we hypothesized that ambulatory electrocardiography (AECG) would be a more sensitive tool for the detection of pacing lead failure compared to increased pacemaker clinic surveillance. Since the Medtronic safety alerts on the 4012, 4082, and 4004 leads, we have followed 261 patients by serial AECG and 165 patients by increased pacemaker clinic surveillance. Lead failures were identified in 75 patients: 68 in the AECG group (31%) and 7 in the clinic group (4%, P < 0.001). Repeat AECG confirmed the lead failure in 38 (97%) of 39 patients in which it could be done. Pacing lead failure documented by AECG could be confirmed by a subsequent clinic assessment in only 15 (25%) of 60 patients evaluated (P < 0.001). The actuarial survival of the 4012 lead was significantly lower in the AECG group compared to the clinic group (56% vs 87% survival at 8 years, P < 0.002). Similar trends were observed for the 4082 and 4004 leads. AECG is a more sensitive method of surveillance for pacemaker lead function compared to pacemaker clinic assessment. AECG should be incorporated into the routine follow-up of pacemaker patients.

Evaluation and outcomes of patients with palpitations

PURPOSE

To determine: (1) the etiologies of palpitations, (2) the usefulness of diagnostic tests in determining the etiologies of palpitations, and (3) the outcomes of patients with palpitations.

PATIENTS AND METHODS

One hundred and ninety consecutive patients presenting with a complaint of palpitations at a university medical center were enrolled in this prospective cohort study. Patients underwent a structured clinical interview and psychiatric screening. The charts were abstracted for results of the physical exam and tests ordered by the primary physician. Assignment of an etiology of palpitations was based on strict adherence to predetermined criteria and achieved by consensus of the two physician investigators. One-year follow-up was obtained in 96% of the patients.

RESULTS

An etiology of palpitations was determined in 84% of the patients. The etiology of palpitations was cardiac in 43%, psychiatric in 31%, miscellaneous in 10%, and unknown in 16%. Forty percent of the etiologies could be determined with the history and physical examination, an electrocardiogram, and/or laboratory data. The 1-year mortality rate was 1.6% (95% confidence interval [CI] 0% to 3.4%) and the 1-year stroke rate was 1.1% (95% CI 0% to 2.6%). Within the first year, 75% of the patients experienced recurrent palpitations. At 1-year follow-up, 89% reported that their health was the same or improved compared to that at enrollment, 19% reported that their work performance was impaired, 12% reported that workdays were missed, and 33% reported accomplishing less than usual work at home.

CONCLUSIONS

The etiology of palpitations can often be diagnosed with a simple initial evaluation. Psychiatric illness accounts for the etiology in nearly one third of all patients. The short-term prognosis of patients with palpitations is excellent with low rates of death and stroke at 1 year, but there is a high rate of recurrence of symptoms and a moderate impact on productivity.

Approach to the patient with palpitations

Palpitations are a common complaint present in up to 16% of outpatients. They are nonspecific and in only 15% of patients do they correlate with a cardiac arrhythmia. The significance of palpitations is related to the presence or absence of underlying cardiac disease, the clinical setting in which palpitations occur, and the characteristics and severity of symptoms. This article presents a concise approach to the evaluation of the ambulatory patient with palpitations.

The accuracy of symptom reporting by patients complaining of palpitations

PURPOSE

To examine the relationship between patients' reports of palpitations and documented arrhythmias.

PATIENTS AND METHODS

Consecutive patients complaining of palpitations and referred for 24-hour ambulatory electrocardiographic monitoring were studied using self-report questionnaires and a structured diagnostic interview. Electrocardiographic results were subsequently analyzed in conjunction with symptom diaries. Positive predictive value was used to estimate the likelihood that a reported symptom coincided with a documented arrhythmia. Sensitivity was calculated as a measure of the likelihood that an arrhythmia would be detected and reported as a symptom.

RESULTS

Positive predictive value was inversely related to somatization, hypochondriacal attitudes, and psychiatric symptoms. It was not related to chronicity of palpitations, previously diagnosed heart disease, more extensive medical care utilization, or clinically significant arrhythmias. Patients were generally insensitive to their arrhythmias, failing to note the vast majority.

CONCLUSIONS

Somatizing and hypochondriacal patients are not more sensitive to or accurately aware of subtle changes in cardiac activity, but rather may be expressing a response bias toward reporting somatic and psychologic distress in general. Apparently, patients do not learn to discriminate and detect cardiac activity more accurately as a result of having more medical care or suffering longer with their symptoms.

Ambulatory arrhythmia screening in symptomatic children and young adults: comparative effectiveness of Holter and telephone event recordings

Effective initial identification of potential cardiac arrhythmias in symptomatic children is difficult due to the infrequency, brief duration, and vague nature of subjective complaints in the young. Although both telephone event and Holter monitoring are used for this purpose, no comparative studies of the initial screening efficacy of either have been performed. A total of 202 consecutive symptomatic children (age 11 days to 26 years, mean 10.2 years) were evaluated for potential cardiac arrhythmias with either 24-h Holter (97 patients) or telephone event (105 patients) recorders and grouped according to the presence or absence of congenital heart defects, normal or abnormal resting electrocardiogram (ECG), and presence or absence of cardiac surgery. The results showed 30% of all recordings (61% event; 14% Holter) failed to substantiate any arrhythmias in spite of subjective symptoms. Event recordings showed a better correlation of sensed symptoms with arrhythmias (32%) compared to Holters (5%) (p < 0.01) with 73% of Holter recordings performed during both asymptomatic and arrhythmia-free 24-h periods. Holter monitoring was more effective in detecting nonsensed and asymptomatic events (8% versus 0.5%, (p < 0.01), among high-risk children. This study demonstrates that although both monitoring devices are applicable to children, each has inherent limitations and usefulness. These must be considered in choosing either device to permit their most optimal and cost-effective application.

Diagnostic evaluation of syncope

Syncope is a common medical problem and is caused by a wide variety of diseases ranging from physiologic derangements with few consequences to conditions that may be immediately life-threatening. Because of the large differential diagnosis, many diagnostic tests are available for its evaluation. However, a cause of syncope is not established in 38% to 47% of patients despite these tests. In those patients in whom a diagnosis can be assigned, the history and physical examination identify a potential cause in 49% to 85%. Furthermore, in 8% of additional patients, history and physical examination are suggestive of causes that need confirmation by specific tests. Routine blood tests rarely yield diagnostically helpful information. In those patients in whom a potential cause for syncope is identified, arrhythmias are diagnosed by electrocardiogram in 2% to 11% of patients, cardiac monitoring in 3% to 27% (telemetry or Holter), stress test in less than 1%, carotid massage in less than 1%, and electrophysiologic studies in less than 3%. Diagnosis of arrhythmias as a cause of syncope is problematic because symptomatic correlation during electrocardiographic monitoring is rarely found (approximately 4%), and as a result, there is no uniform agreement on diagnostic criteria for abnormalities. Similar problems exist in the use of electrophysiologic studies. Upright tilt testing and psychiatric examination may be useful in evaluation of recurrent syncope of unknown cause in patients without organic heart disease. Based on the results of recent studies, strategies for evaluation of patients with syncope are possible that utilize selective and goal-directed diagnostic testing.

Spontaneous variability in ventricular ectopic activity during chronic antiarrhythmic therapy

Previous determinations of variability in frequency of ventricular arrhythmias have been based on repeated recordings obtained in the absence of therapy. We evaluate variability during "effective" treatment with antiarrhythmic drugs. Variability in the percent suppression of premature ventricular complexes (PVCs) was determined in 55 patients with chronic arrhythmias who underwent multiple ambulatory electrocardiographic recordings during evaluation of chronic therapy with antiarrhythmic drugs initially determined to be effective, which was defined as 70% or more reduction in total PVC frequency or 90% or more reduction in repetitive forms. During chronic therapy, total PVCs were suppressed by 92%, averaged after a logarithmic transformation step, and repetitive beats were suppressed by 88%. Variability in suppression was substantial. The one-sided 95% confidence intervals required a fall in suppression of total PVCs to 40% or less to exceed limits of spontaneous variability and of repetitive PVCs to 66% or less. Suppression declined at least once during therapy to less than 60% for total PVCs in 24 of 55 patients (44%) and to less than 80% for repetitive PVCs in 13 of 33 patients (39%); nine patients (16%) showed increases in PVC frequency at least once to levels above pretreatment baseline. Seven subgroups were analyzed for their effects on variability and loss of suppression: age, gender, disease etiology, cardiac function, baseline PVC frequency, use of beta-blockers, and class of antiarrhythmic drug. Differences in confidence bounds and loss of suppression were found to be determined in a complex way by subgroup differences in variability and in initial levels of PVC suppression. Variability was greater for patient subgroups with greater PVC frequency, beta-blocker therapy, and non-coronary artery disease. However, clinical loss of suppression was more common only in more elderly patients and those with worse cardiac function. In summary, substantial variability in arrhythmia frequency occurs during effective antiarrhythmic therapy, and the 95% confidence limits of spontaneous variability are broad and determined in a complex way. Careful consideration should be given before concluding on the basis of a single Holter test that changes (increases) in arrhythmia frequency, especially in certain subgroups, are caused by treatment failure.

Permanent pacemaker placement in chronic atrial fibrillation associated with intermittent AV block and cerebral symptoms

We examined the hypothesis that a greater than or equal to 2 second pause detected on 24-hour Holter monitoring in patients with persistent atrial fibrillation and complaints of syncope or dizziness lacked sufficient specificity to warrant implantation of a permanent pacemaker. We retrospectively reviewed cases from our 24-hour electrocardiographic (Holter) monitoring data base. A total of 411 consecutive Holter monitoring records demonstrating persistent atrial fibrillation obtained during a 5-year period (1982 to 1987) were examined. One hundred and five (26%) patients had cerebral symptoms (dizziness or syncope) as a primary indication for monitoring 80 (76%) patients were identified with documented ventricular pauses of greater than or equal to 2 seconds. Three hundred and six patients (74%) underwent 24-hour monitoring without cerebral symptoms as an indication and 209 (68%) patients had greater than or equal to 2-second pauses. Clinical information was available in 164 (50 symptomatic and 114 asymptomatic) patients. There were no significant differences in the clinical or Holter findings between the two groups. Of the 50 symptomatic patients, 15 (30%) underwent permanent pacemaker placement and the remaining 35 (70%) were managed conservatively during a mean follow-up of 23 +/- 5 months. Eleven of 15 paced (73%) and 31 of 35 (89%) nonpaced patients experienced resolution of their cerebral symptoms (NS). The sensitivity of Holter monitoring in detecting pauses of greater than or equal to 2 seconds in patients with cerebral symptoms was high (76%), but the specificity (32%) and positive predictive values (28%) were low.(ABSTRACT TRUNCATED AT 250 WORDS)

The value of Holter monitoring in evaluating the elderly patient who falls

Ambulatory cardiac (Holter) monitoring is often recommended in the routine evaluation of patients who fall; however, the prevalence of arrhythmias in old people is high, and the usefulness of such monitoring is unproven. As part of a large study of institutionalized elderly fallers, we compared Holter findings of fallers (N = 51) with a group of nonfallers (N = 27) having similar medical and demographic characteristics. Prevalence of ventricular arrhythmias was 82% in each group, and all patients had supraventricular arrhythmias. The mean number of ventricular and supraventricular couplets and runs did not differ between groups. There was no difference in severity of arrhythmias between fallers and nonfallers; in fact, fallers had slightly fewer Lown 4B arrhythmias than nonfallers (10% vs 18%, NS). Prevalence of heart disease was 78% in both groups and was associated with increased ventricular ectopy in the form of runs and couplets (P less than .05). No symptoms were reported during the Holter monitoring. We conclude that Holter monitoring should not be a routine part of the work-up of the patient who falls.

Diagnostic utility of memory equipped transtelephonic monitors

The diagnostic utility of memory-equipped transtelephonic electrocardiographic monitors was evaluated in a series of 31 patients referred for evaluation of unexplained syncope (16), presyncope (8), or palpitations (7). Previous nondiagnostic workups included 4 +/- 1 days (mean +/- standard error of the mean) of 24-hour Holter and/or in-hospital telemetric monitoring per patient. The duration of monitoring averaged 31 +/- 2 days per patient. Electrocardiographic recordings were made during a typical symptom episode in 9 of 31 (29%) patients, including 0 of 16 with syncope, 3 of 8 (37%) with presyncope, and 6 of 7 (86%) with palpitations (p less than .001). The probability of recording typical symptoms was strongly influenced by their previous frequency. Potentially causal arrhythmias were documented in 5 of 7 (71%) patients with palpitations, but in none of the other symptom subgroups (p less than .001). Monitoring led to changes in therapy in only two patients. During followup of 9 +/- 1 months, symptoms continued in 4 of 16 (25%) with syncope, 7 of 8 (87%) with presyncope, and 7 of 7 (100%) with palpitations (p = .001). The diagnostic utility of these devices thus appears to be low in patients with previously unexplained syncope or presyncope. The yield was high in those monitored for palpitations, which may be in part attributable to the greater frequency of symptoms observed in this group.

Changes in spontaneous variability of ventricular ectopic activity as a function of time in patients with chronic arrhythmias

Previous determinations of spontaneous variability in ventricular arrhythmia have often been based on measurements from consecutive days in small patient populations, whereas clinical determinations of drug efficacy typically compare measurements at intervals of 1 week and longer to baseline. We, therefore, sought to determine whether spontaneous arrhythmia variability changes as a function of time during periods ranging from 1 day to 1 year or longer. The percent reduction in the frequency of total premature ventricular complexes (PVCs) and repetitive ventricular beats required to show true drug effect rather than spontaneous variability in PVCs was determined in 47 consecutive patients with chronic ventricular arrhythmias who underwent multiple ambulatory monitor recordings while off active drug treatment (during placebo therapy). The variability in PVC rate was determined during the intervals of 1 day, 1 week, 2 weeks, 3 weeks, 4 weeks, and 1 year or longer. The percent reductions in total PVCs required to exceed the 95% confidence limits of spontaneous variability at these intervals were 55%, 85%, 86%, 93%, 96%, and 96%, respectively. Corresponding values for repetitive beats were 75%, 95%, 92%, 95%, 94%, and 98%, respectively. The percent increase in total PVCs and repetitive beats required to establish "arrhythmia aggravation" caused by an antiarrhythmic drug with a 95% confidence limit also was calculated for this study population and was 124% and 303%, respectively, at 1-day intervals and 2,269% and 4,091%, respectively, at 1-year (or longer) intervals for the 24-hour monitor recordings. Variability was not substantially affected by underlying heart disease or ejection fraction. PVC rate showed a modest negative correlation with variability (r = 0.3). Thus, variability is substantially greater at 1 week, the usual time for clinical assessment of antiarrhythmic drug efficacy, than at 1 day (p less than 0.01). Suppression of more than 85% of total PVCs and more than 95% of repetitive beats appears to be necessary after 1-2 weeks to be confident of a true drug effect. Even greater variability is observed after 1 month and up to 1 year so that reductions of up to 95% in total PVCs and 98% in repetitive beats may represent spontaneous change.(ABSTRACT TRUNCATED AT 400 WORDS)

Noninvasive testing for ventricular arrhythmias

Before treating patients with ventricular arrhythmias, it is important to classify the arrhythmias as benign, potentially lethal, or lethal. The vast majority of patients seen in clinical practice have benign or potentially lethal forms, which can be evaluated with noninvasive electrocardiographic techniques, such as continuous Holter monitoring and exercise testing. Lethal ventricular arrhythmias are probably best managed with invasive electrophysiologic testing. Quantitative Holter monitoring is essential both before starting antiarrhythmic therapy to establish a baseline and after starting therapy to determine whether treatment is effective, ineffective, or causing proarrhythmia. Whether adequate suppression of ventricular arrhythmias prevents sudden cardiac death is still unknown but is currently being evaluated by the Cardiac Arrhythmia Suppression Trial of the National Institutes of Health, Bethesda. The results are expected in the mid-1990s.

Utility of ambulatory electrocardiography in detecting pacemaker dysfunction in the early postimplantation period

The value of ambulatory electrocardiography (AECG) in detecting pacemaker dysfunction before hospital discharge was assessed in 100 patients a mean of 1.2 days after pacemaker implantation. The incidence of permanent pacemaker dysfunction detected by AECG in the early postimplantation period, the frequency that pacemaker dysfunction detected by AECG was not detected by telemetric monitoring and the frequency that results of AECG led to pacemaker reprogramming before hospital discharge were determined. AECG detected at least 1 type of pacemaker dysfunction in 35% of patients and routine telemetry identified the abnormality in only 8% (p less than 0.001). Pacemaker dysfunction occurred in 42% of patients with dual-chamber devices and 27% of those with single-chamber devices (difference not significant). In the 35 patients who had pacemaker malfunction, a total of 50 instances of pacemaker dysfunction were detected. Failure of atrial capture occurred in 2% of patients, failure of atrial sensing in 9%, failure of atrial output in 1%, failure of ventricular capture in 8%, failure of ventricular sensing in 14%, failure of ventricular output due to myopotential inhibition in 11% and pacemaker-mediated tachycardia in 5%. The results of the AECG led to a clinical intervention in 22 patients (pacemaker reprogramming in 21 patients and lead repositioning in 1 patient) in whom no pacemaker dysfunction was suspected on the basis of telemetry or clinical symptoms. In conclusion, AECG provides additional benefit beyond that of routine telemetry monitoring in identifying pacemaker dysfunction in the early period after implantation.

Diagnostic and prognostic implications of recurrences in patients with syncope

The incidence and the diagnostic and prognostic implications of recurrences in 433 patients enrolled in a prospective syncope study are reported. Over a mean follow-up of 30 months, 146 patients had recurrent syncope. Patients with an initial diagnosis of a cardiovascular cause of syncope had a recurrence rate of 31 percent, patients with a noncardiovascular cause had a recurrence rate of 36 percent, and patients with syncope of unknown origin had a recurrence rate of 43 percent at three years (these differences were not significant; the minimum for any two-way comparison was p greater than or equal to 0.11). In eight of the 191 patients in whom a cause of syncope could not be found on initial evaluation, a diagnosis was assigned in follow-up after recurrent syncope. Recurrences led to major morbidity in eight of 146 patients (5 percent) and minor trauma in 10 patients (7 percent). Using recurrence as a time-dependent variable in the Cox models, it was found that this variable was not a significant predictor of overall mortality or sudden death. It is concluded that recurrences are common in patients with syncope, but new diagnosis are rarely established on the basis of evaluation of recurrences. Recurrences are not predictors of mortality or sudden death.

Transtelephonic monitoring: documentation of transient cardiac rhythm disturbances

Symptoms suggestive of a transient disturbance in cardiac rhythm often prompt a patient to seek medical help. Transtelephonic monitoring (TTM) can document the rhythm at the exact time that the patient is experiencing clinical symptoms. Our experience with TTM from 1979 to 1983 involved 526 patients who had one or more of the following symptoms: near-syncope (in 121), light-headedness (in 248), intermittent palpitations (in 281), and tachycardia (in 321). Patients suspected of having a life-threatening arrhythmia after the initial history, physical examination, and laboratory testing were excluded from this study. Of the 526 patients, 259 transmitted with the TTM device during a typical symptomatic episode; 186 had an arrhythmia identified, and 73 had a normal cardiac rhythm. The mean duration (+/- SD) from receipt of the TTM system until the first transmission was 48 +/- 80 days. The most frequent diagnoses at transmission were supraventricular tachycardia (in 80 patients) and sinus tachycardia (in 46). This study showed that TTM is effective in documenting infrequent arrhythmias and in establishing the temporal relationship between clinical symptoms and the patient's heart rhythm. TTM is a useful, practical, and efficient addition to more conventional means of electrocardiographic monitoring for patients with non-life-threatening arrhythmias.

Prolonged electrocardiographic monitoring in patients with syncope. Importance of frequent or repetitive ventricular ectopy

The purposes of this study were to document the findings on prolonged electrocardiographic monitoring in patients with syncope, correlate these findings with symptoms during monitoring, and define the prognostic importance of these findings. A total of 235 patients with syncope in whom a cause was not assigned or suggested by the initial history, physical examination, and electrocardiography were studied. Although a variety of arrhythmias were documented during monitoring, the vast majority of arrhythmias were of short duration and did not produce symptoms. At two years, the patients with frequent or paired premature ventricular contractions (PVCs) when compared with patients with rare PVCs, had a higher incidence of sudden death (18.2 percent versus 4.0 percent; p less than 0.001) and higher overall mortality (28.3 percent versus 10.8 percent; p less than 0.003). Similarly, patients with ventricular tachycardia, when compared with patients with rare PVCs, had a higher incidence of sudden death (18.7 percent versus 4.0 percent; p less than 0.0001) and higher overall mortality (36.5 percent versus 10.8 percent; p less than 0.00001). Cox regression analyses revealed that frequent or repetitive PVCs and sinus pauses were independent electrocardiographic predictors of sudden death and mortality in patients presenting with syncope. Therefore, patients with syncope and frequent or repetitive ventricular ectopy or sinus pauses constitute a high-risk subgroup and may be candidates for more extensive diagnostic evaluation.

Advances in single-chamber pacemaker diagnostic data

Diagnostic data, which is Holter-type information documenting the pulse generators' interaction with the patient over time, are now available in single chamber pulse generators from at least six manufacturers. Diagnostic data are available in bradycardia, tachycardia, and rate-responsive pulse generators. Six hypothetical examples discuss the clinical utility of advanced diagnostic data. Three examples examine the use of diagnostic data with bradycardia pulse generators. These use rate histograms or high-rate counters to solve programming and patient problems. Two examples involve antitachycardia pulse generators and the uses for diagnostic data in both chronic and acute cases. One example deals with the use of maximum and minimum temperature diagnostics in proper programming of a temperature rate-responsive device.

Syncope in the elderly

This report describes the evaluation of syncope in 210 elderly patients as compared with 190 younger patients. The elderly group had a mean age of 71 years (range 60 to 90) and the younger group had a mean age of 39 years (range 15 to 59). A cardiovascular cause was found in 33.8 percent of the elderly and in 16.8 percent of the young (p = 0.0001), a noncardiovascular cause in 26.7 percent of the elderly and 37.9 percent of the young (p = 0.02), and unknown cause in 38.5 percent of the elderly and 45.3 percent of the young (NS). Prolonged electrocardiographic monitoring established the diagnosis in 17 percent of the elderly but in only 8 percent of the young (p = 0.008). Syncope resulted in trauma in 39 percent of the elderly and in 32 percent of the young, but the elderly more often had major trauma. The two-year overall mortality was 26.9 +/- 3.4 percent in the elderly and 8.3 +/- 2.1 percent in the young (p less than 0.0001). The overall mortality and incidence of sudden death in the elderly with a cardiovascular diagnosis were similar to those in the young; however, in the elderly with a noncardiovascular diagnosis and syncope of unknown cause, the mortality and incidence of sudden death were higher. Multivariate analyses using mortality and sudden death as endpoints revealed that a cardiovascular cause of syncope was a very strong risk factor. In patients with a noncardiovascular cause or unknown cause of syncope, a history of congestive heart failure, older age, and male sex are important prognostic factors.

Incidence of complex ventricular arrhythmias in asymptomatic patients with recent myocardial infarction

The incidence of ventricular extrasystoles (VES) was documented in 50 patients with recent uncomplicated myocardial infarction, with a 72-h two-channel ambulatory electrocardiogram. All patients were free of symptoms of arrhythmias; unstable angina pectoris and heart failure were absent. A total of 82% of the patients had VES: 23/50 patients had multiform or complex VES, 8/50 patients had ventricular tachycardia. VES were independent of heart rate and stable angina pectoris. Thus, frequent and complex VES are common in asymptomatic patients with uncomplicated recent myocardial infarction. Even in the absence of symptoms, ambulatory electrocardiography is useful. The prognostic significance of asymptomatic complex VES in these patients remains unsettled.

Evaluation of prognostic classifications for patients with syncope

To evaluate two published sets of prognostic classifications for patients with syncope, 176 consecutive patients who presented to an emergency room with syncope were studied. Although relatively few patients had cardiac syncope, these data confirmed their high one-year mortality. At the other extreme, it was also confirmed that patients who were 30 years of age or less or 70 years of age or less and had vasovagal/psychogenic syncope or syncope of unknown cause had a benign prognosis, with only two deaths in 225 patients in pooled data. However, these data did not confirm the previously reported prognoses for "medium-risk patients" or for patients with diagnosable noncardiovascular causes of syncope, largely because of differences in criteria for patient eligibility. It is concluded that available data allow over 70 percent of patients with syncope to be placed into either very-high or very-low-risk groups. However, further investigation, taking into account differences in patient selection criteria, will be required before accurate prognostic classifications can be derived for the nearly 30 percent of patients who do not fall into one of these extreme prognostic categories.

The value of electrophysiologic studies in syncope of undetermined origin: report of 150 cases

A prospective study examined the diagnostic yield and therapeutic efficacy of electrophysiologic studies in patients with SUO. We defined SUO as those syncopal or near-syncopal events remaining unexplained after a standardized, noninvasive evaluation that included a history, physical examination, routine laboratory screening, EEG, nuclear brain scan or CAT scan, 12-lead ECG, chest x-ray, orthostatic vital signs, bedside carotid sinus massage, and at least 24 hours of continuous ECG monitoring. The 150 SUO patients included 95 men and 55 women (mean age 62.0 years); 35 had recurrent SUO, 75 (50%) had organic heart disease, and 129 (86%) had abnormal ECGs. There were 162 abnormal electrophysiologic findings that could explain the SUO uncovered in 112 patients, a diagnostic yield of 75%: one finding in 71 patients, two findings in 32, and three findings in nine. These findings were: His-Purkinje disease in 49 patients (30%), inducible ventricular arrhythmias in 36 (22%), AV nodal disease in 20 (12%), sinus node disease in 19 (12%), inducible supraventricular arrhythmias in 18 (11%), carotid sinus hypersensitivity (not elicited by carotid sinus massage prior to electrophysiologic studies) in 15 (9%), and hypervagotonia in five (3%). When electrophysiologic study findings were classified as clearly abnormal or borderline, 54 patients had at least one clearly abnormal finding, a diagnostic yield of 36%. Subgroups of patients presenting with only a single SUO event, no evidence of organic heart disease, or normal baseline ECGs all had substantial diagnostic yields during electrophysiologic studies. Follow-up data in 137 patients (91%) (mean 31 months) showed recurrences in 16 of 34 patients (47%) without and 15 of 103 patients (15%) with electrophysiologic findings despite therapy directed by electrophysiologic testing (p less than 0.0005). This study and a review of the literature indicate that electrophysiologic testing is useful in elucidating the causes of SUO and directing therapy. A significant number of patients benefit from electrophysiologic studies, even when only clearly abnormal findings are considered diagnostic, when only a single syncopal event has occurred, or whether or not organic heart disease or an abnormal ECG is present.

Some aspects of neurological presentation of patients with important cardiac arrhythmias requiring pacemaker therapy: a preliminary report

We report the short- and long-term effects of pacing on 82 patients presenting with significant bradyarrhythmias and neurological symptoms. The 3 categories of neurological symptoms were dizziness alone, syncope with or without dizziness and focal neurological symptoms with a history of dizziness or syncope.

Can cardiac death be predicted from an ambulatory 24-hour ECG?

For the prediction of cardiac death significant prognostic information can be derived from ambulatory 24-hr ECGs when they are recorded on indication in the cardiological outpatient-clinic. In both CHD and non-CHD patients, ventricular arrhythmias, supraventricular arrhythmias and conduction disturbances are all of importance in the assessment of prognosis. These conclusions are based on a review of all 123 cardiac deaths and 433 randomly selected survivors from a cohort of 5095 patients who underwent 24-hr ECG-recording on clinical indication and whose survival status was ascertained 18 months after the recording date.

Athlete's bradycardia as an embolising disorder? Symptomatic arrhythmias in patients aged less than 50 years

One hundred and sixty consecutive patients less than 50 years of age (mean 38 years) referred for long term electrocardiographic recording were evaluated retrospectively. Significant cardiac arrhythmias were detected in 51 of 107 (48%) patients examined because of syncope or dizzy spells or both. Of 39 patients examined for cardiac complaints or presumed complex arrhythmias, 15 (38%) had significant arrhythmias. Of 14 patients examined because of otherwise unexplained strokes, nine had slow sinus rates. Of these, one patient had recently undertaken moderately intensive athletic activity and four had been undertaking vigorous athletic activities for several years. All of the 12 active athletes who were followed up on account of syncope or dizzy spells were free of symptoms after reducing their athletic activities. The cardiac rhythm returned to normal in four out of five who underwent repeat long term electrocardiographic recording. It is suggested that vigorous athletic activity in subjects of 30-50 years of age may transform the adaptative bradycardia of the athlete into a condition similar to the embolising sick sinus syndrome.

Carotid sinus hypersensitivity. Case report and review of the literature

Carotid sinus hypersensitivity is a potentially treatable cause of recurrent neurologic symptoms. Diagnosis depends upon recognizing the variable presentation of symptomatic carotid sinus hypersensitivity, and noting an exaggerated cardiovascular response to carotid sinus massage associated with neurologic symptoms. Once the diagnosis of symptomatic carotid sinus hypersensitivity has been established, it is important to delineate the type of hypersensitivity present, because identification of the vasodepressor response has important therapeutic implications.

[Value of ECG-telephone transmission in determining symptomatic heart-rhythm disorders]

The ECG-telephone-transmission (TTM) was used to record an ECG-strip during a typical symptomatic period in patients complaining of symptoms possibly caused by arrhythmias (palpitations, dizziness, paroxysm tachycardia, pulse irregularities; angina and dyspnea only if other reasons could be excluded). Patients complaining of syncope only were not admitted, because of the inability to make a telephone call successfully during such a symptomatic period. The ECG was transmitted to the CCU using a frequency modulation technique. In 60% of 196 patients an ECG-TTM could be achieved during a typical symptomatic period, whereas arrhythmias as cause for the symptoms could be excluded in 51 patients (26%). The remaining 66 patients (34%) demonstrated various arrhythmias ranging from simple SVPB and PVC to total AV-block and sustained VT. TTM, an easy-to-perform and cost-effective method allowed a successful ECG registration during a symptomatic period in almost two-thirds of symptomatic patients. In these patients arrhythmias could be verified or excluded as cause of the symptoms.

Ambulatory electrocardiographic monitoring in 100 healthy teenage boys

Ambulatory monitoring of the electrocardiogram in 100 healthy 14 to 16 year old boys showed heart rates ranging from 45 to 200 beats/minute during the day and from 23 to 95 beats/minute during sleep. Sinus arrhythmia was present in all cases and was the only variation noted in 17%. Sudden variations in the PP interval occurred in 41%, but a precise diagnosis of the mechanism was usually impossible; 15% had changes compatible with sinus arrest or temporary complete sinoatrial block, and one boy had a pattern compatible with type II second degree sinoatrial block. Escape rhythms were noted in 26%, first degree atrioventricular block in 12%, and second degree atrioventricular block (Mobitz type I) in 11%. Mobitz type II second degree atrioventricular block was seen on one occasion in one boy. Ventricular extrasystoles seen in 41% were of uniform morphology in 75% and multiform in 25%. Short episodes of ventricular tachycardia were recorded in 3%.