The American Heart Association classifies monitored patients into 3 categories. The aims of this study were to (1) investigate how patients are assigned according to the American Heart Association classification, (2) determine the number and type of arrhythmic events experienced by these patients, and (3) describe subsequent changes in management. A prospective observational study design was used. All patients assigned to telemetry during a 3-month period were consecutively enrolled in our study. Data were collected 24/7. Only arrhythmias that might require a change in management were recorded. Monitor watchers at the central monitoring station completed a standard data sheet assessing 64 variables. These data, as well as medical records, were reviewed by the investigator. Overall, 1,194 patients were included. Eighteen percent of the patients were assigned to American Heart Association class I (monitoring indicated), 71% to class II (monitoring may be of benefit), and 11% to class III (monitoring not indicated). The overall arrhythmia event rate was 33%. Forty-three percent of class I patients, 28% of class II patients, and 47% of class III patients experienced arrhythmia events. Change in management occurred in 25% of class I patients, 14% of class II patients, and 29% of class III patients. Although the number of class III indications should have been reduced, nearly 1/2 of class III patients experienced arrhythmia events and 1/3 of them received management changes. This outcome challenges existing guidelines. In conclusion, most patients in this study were monitored appropriately, according to class I and II indications.
In 2004, the American Heart Association (AHA) published the AHA Practice Standards for Electrocardiographic Monitoring in Hospital Settings . Neither appropriate classifications nor patient outcome is typically evaluated according to these recommendations. Appropriate telemetry monitoring is suggested in response to severe arrhythmia treated with ≥1 interventions. Arrhythmias of any type are detected in 24% to 33% of all patients. Four percent to 28% of all observed events result in a change of management. Only 0.8% to 1.0% of the patient population is transferred to intensive care units because of arrhythmias. Two studies claim that the primary arrhythmia causes sudden death in monitored patients only to a limited extent, if at all. However, those were single-center studies using guidelines from 1991. Only 1 study, the Practical Use of the Latest Standards for Electrocardiography trial conducted a multisite randomized clinical trial to evaluate the AHA recommendations regarding under- and overmonitoring of cardiac patients. Although that study included a large number of patients, observations continued for only 5 days in each hospital and therefore provided only a snapshot of electrocardiographic monitoring practice. More studies using the AHA classifications are warranted to evaluate these outcomes. Therefore, the aims of the present study were to (1) investigate how patients are assigned according to the AHA classification of cardiac arrhythmia monitoring, (2) describe the number and type of arrhythmic events, and (3) describe subsequent changes in management.
Methods
A prospective observational study design was used, with follow-up measurements from telemetry admission to discharge from the hospital. The study was performed at Haukeland University Hospital, Bergen, Norway for 3 months, from November 2009 to January 2010. This hospital has 1,100 inpatient beds and 107,000 somatic admissions per year. The hospital has 19 remote wireless telemetry units, which are monitored from a central station at the medical intensive care unit. The medical intensive care unit is equipped with a Philips EASI lead telemetry system (Philip Health Care, Eindhoven, the Netherlands) with 48-hour recall and memory and is staffed with nurses providing 24/7 surveillance. Few local consensus criteria exist to determine which patients are eligible for in-hospital telemetry monitoring. Cardiologists regularly review admissions to ensure that low-risk patients are discharged from telemetry when priorities require otherwise.
Our sample consisted of 1,194 patients in adult units. All patients assigned to telemetry in a non–intensive care setting were consecutively enrolled during a 3-month period. None were excluded, and all patients underwent follow-up. The study population included both cardiac and noncardiac patients.
Classifications and patient outcome were based on the AHA Practice Standards for Electrocardiographic Monitoring in Hospital Settings , as listed in Table 1 . The distribution of patients meeting AHA class I to III indications was recorded.
| Class I Indications for Cardiac Arrhythmia Monitoring | Time Frame of Monitoring |
|---|---|
| 1. Patients resuscitated from cardiac arrest | Until ICD implanted |
| 2. Patients in the early phase of acute coronary syndrome | Minimum 24 h, until 24 h after complications resolved |
| 3. Patients with newly diagnosed high-risk coronary lesions | Until PCI |
| 4. Adults who have undergone cardiac surgery | Minimum 48–72 h or discharge |
| 5. Patients who have undergone nonurgent PCI with complications | Minimum 24 h |
| 6. Patients who have undergone implantation of an ICD lead or a pacemaker lead and are considered pacemaker dependent | 12–24 h |
| 7. Patients with a temporary pacemaker or transcutaneous pads | Until pacing no longer necessary or replaced with a permanent device |
| 8. Patients with AV block | Until permanent pacemaker |
| 9. Patients with arrhythmias complicating WPW syndrome with rapid anterograde conduction over an accessory pathway | Until RFA |
| 10. Patients with long QT syndrome and associated ventricular arrhythmias | Until proarrhythmic drug is discontinued |
| 11. Patients receiving IABP | Until weaned from IABP |
| 12. Patients with acute heart failure or pulmonary edema | 24 h after symptoms resolved |
| 13. Patients with indications for intensive care | Until hemodynamically and respiratory stable |
| 14. Patients undergoing diagnostic or therapeutic procedures requiring conscious sedation or anesthesia | Until awake and hemodynamically stable |
| Class II Indications for Cardiac Arrhythmia Monitoring | Time Frame of Monitoring |
|---|---|
| 1. Patients with postacute MI | 24–48 h |
| 2. Patients with chest pain syndromes | 12–24 h or until negative biomarkers |
| 3. Patients with uncomplicated nonurgent PCI | 12–24 h |
| 4. Patients who are administered an antiarrhythmic drug or who require adjustment of drugs for rate control with chronic atrial tachyarrhythmia | With antiarrhythmic drugs and high risk of proarrhythmia: consider class I indication |
| 5. Patients who have undergone implantation of a pacemaker lead and are not pacemaker dependent | 12–24 h |
| 6. Patients who have undergone uncomplicated ablation | Normally not necessary. 12–24 h with incessant rapid tachycardia or AV junction ablation with pacemaker implantation |
| 7. Patients who have undergone routine coronary angiography | Normally not necessary, only for observation for symptomatic bradycardia |
| 8. Patients with subacute heart failure | In subacute phase, when therapy is adjusted |
| 9. Patients who are being evaluated for syncope | 24–48 h with unknown origin |
| 10. Patients with do-not-resuscitate orders with arrhythmias that cause discomfort | Until optimum rate control is achieved |
A standard data abstraction sheet specifically developed for this study was used to record baseline information (age, gender, the unit from which the patient was admitted, admission diagnosis, telemetry indications, discharge diagnosis, arrhythmias, and change in management). Discharge diagnosis was based on the International Statistical Classification of Diseases version 10. Arrhythmias and management changes were recorded for the duration of the patients’ telemetry assessment. Only the first arrhythmia event was noted. The medical records of all patients were reviewed.
Data were collected 24 hours a day, on weekdays, and on weekends. Monitor watchers located at the central monitoring station completed each standard data abstraction sheet, which was then reviewed by the investigator. The investigator followed all patients daily until discharge from telemetry, tabulated detailed summaries of events occurring, and followed management changes. Classifications according to the AHA standards based on admission diagnoses, telemetry indications, and discharge diagnoses were made by the investigator and then reviewed by 2 cardiologists.
The study was approved by the Norwegian Social Science Data Services (2009/22074) and the Institutional Review Board at Haukeland University Hospital (2010/1250). Approval from the Regional Committee for Medical Research Ethics (2009/174) did not require full formal committee review.
Descriptive analyses were carried out by calculating means, SDs, and ranges for normally distributed continuous variables, and absolute numbers and percentages were calculated for categorical variables. All data were analyzed using the Statistical Package for the Social Sciences, version 18 (SPSS, Chicago, Illinois).
Results
The demographic and baseline characteristics for all the 1,194 patients are listed in Table 2 . Classification of the patients according to admission diagnosis and the AHA practice standards revealed that 18% of the patients were categorized as class I (indicated in most, if not all patients), 71% as class II (may be of benefit in some patients but is not considered essential for all patients), and 11% as class III (not indicated because the patient’s risk of a serious event is so low that monitoring has no therapeutic benefit). The most common admission diagnoses were arrhythmia and acute coronary syndrome in class I patients, chest pain in class II patients, and dizziness in class III patients ( Table 3 ). However, when classifying by telemetry indication or discharge diagnosis, the number of patients and the type of diagnosis in each class differed substantially. Specifically, a large number of patients admitted with chest pain were reclassified from class II to class I after an acute coronary syndrome diagnosis was confirmed.
| Variable | Value, n (%) |
|---|---|
| Men | 739 (62) |
| Age (yrs) | 64 ± 18 |
| AHA classification | |
| Class I | 218 (18) |
| Class II | 847 (71) |
| Class III | 129 (11) |
| Admission meeting AHA classes I and II | 1,065 (89) |
| Outcome measures | |
| Overall incidence of telemetry events | 390 (33) |
| Overall change in managements | 245 (21) |
| Overall transfers to intensive care unit | 19 (1.6) |
| Overall deaths | 20 (1.7) |
| Median telemetry LOS, h (SD) | 21 (44) |
| LOS class I, median ± SD | 24 ± 54 |
| LOS class II, median ± SD | 20 ± 35 |
| LOS class III, median ± SD | 21 ± 69 |
| Most common admission diagnoses | |
| Chest pain | 494 (41) |
| Atrial fibrillation and RFA | 127 (11) |
| Syncope | 100 (8) |
| Elective PCI | 75 (6) |
| Respiratory distress | 73 (6) |
| Intoxication | 37 (3) |
| Most common arrhythmias | |
| Atrial fibrillation and flutter | 153 (13) |
| Nonsustained ventricular tachycardia | 82 (7) |
| Sinus tachycardia | 40 (3) |
| Most common admission source | |
| Department of heart disease | 663 (56) |
| Chest pain unit in the emergency department | 365 (31) |
| General medical wards | 116 (10) |
| General surgical wards | 27 (2) |
| PCI | 278 (23) |
| Diabetes mellitus | 160 (13) |
| Hypertension | 368 (31) |
| Variable | Total (%) | Class I (%) | Class II (%) | Class III (%) |
|---|---|---|---|---|
| Classification by admission diagnosis | 1,194 (100) | 217 (18) | 849 (71) | 128 (11) |
| Chest pain | 494 (41) | 0 | 494 (58) | 0 |
| Acute coronary syndrome | 127 (11) | 52 (24) | 75 (9) | 0 |
| Arrhythmias | 189 (16) | 68 (31) | 108 (13) | 13 (10) |
| Heart failure | 73 (6) | 1 | 72 (9) | 0 |
| Syncope or dizziness | 127 (11) | 1 | 100 (12) | 26 (20) |
| Intoxication | 37 (3) | 37 (17) | 0 | 0 |
| Nonspecific infection or sepsis | 22 (2) | 7 (3) | 0 | 15 (12) |
| Other ∗ | 125 (10) | 51 (23) | 0 | 74 (57) |
| Classification by telemetry indication | 1,194 (100) | 527 (44) | 653 (55) | 14 (1) |
| Chest pain | 406 (34) | 0 | 406 (62) | 0 |
| Acute coronary syndrome | 215 (18) | 138 (26) | 77 (12) | 0 |
| Arrhythmias | 368 (31) | 301 (57) | 57 (9) | 10 (71) |
| Heart failure | 10 (1) | 0 | 10 (2) | 0 |
| Syncope | 86 (7) | 0 | 86 (13) | 0 |
| Intoxication | 36 (3) | 35 (7) | 0 | 1 (7) |
| Nonspecific infection or sepsis | 0 | 0 | 0 | 0 |
| Other † | 73 (6) | 53 (10) | 17 (3) | 3 (21) |
| Classification by discharge diagnosis | 1,194 (100) | 645 (54) | 370 (31) | 179 (15) |
| Chest pain | 138 (12) | 0 | 138 (37) | 0 |
| Acute coronary syndrome | 422 (35) | 344 (53) | 78 (21) | 0 |
| Arrhythmias | 226 (19) | 159 (25) | 59 (16) | 8 (4) |
| Heart failure | 55 (5) | 14 (2) | 41 (11) | 0 |
| Syncope | 35 (3) | 0 | 35 (9) | 0 |
| Nonspecific infection or sepsis | 42 (4) | 26 (4) | 0 | 16 (9) |
| Intoxication | 41 (3) | 41 (6) | 0 | 0 |
| Other ‡ | 235 (20) | 61 (9) | 19 (5) | 155 (87) |
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