Ambulatory ECG monitoring (48hrs or 72hrs) is recommended when symptoms such as dizziness, fainting, low blood pressure, prolonged fatigue, or palpitations persist without a definitive diagnosis from a resting ECG. Extended monitoring over 7 or 14 days allows for the detection of transient or intermittent arrhythmias.
Detection of Arrhythmias:
Atrial Fibrillation (A Fib) / Atrial Flutter
Heart Blocks
Tachycardia / Bradycardia
Pauses, Arrest
Prolonged QT Interval
Cardiomyopathy
Symptomatic Patients:
Dizziness
Syncope, Pre-syncope
Prolonged Fatigue
Palpitations
Evaluation when symptoms continue without a definitive diagnosis
from a resting ECG.
Evaluation of Therapeutic Interventions:
Medications
Evaluation of Pacemaker/ICD Function:
Single and dual-chamber devices
Detection of Myocardial Ischemia:
Anti-ischemic therapy evaluation
Ischemic heart disease
Post-myocardial infarction
Valvular heart disease
Holter monitoring has several limitations:
Intermittent Arrhythmias: The device may miss arrhythmias that occur infrequently or only during specific activities.
Patient Compliance: The accuracy of Holter monitoring depends on the patient's adherence to wearing the device and documenting symptoms correctly.
Limited Scope: While Holter monitoring is effective for detecting arrhythmias, it does not assess other cardiac issues like ischemic heart disease or provide insight into coronary artery blockages.
Uncertain Etiology: Holter monitoring may not detect the root cause in cases where symptoms persist without a clear diagnosis from a resting ECG.
Stress echocardiography provides real-time assessment of cardiac function under stress and is particularly effective for identifying myocardial ischemia and wall motion abnormalities, offering valuable insights into overall cardiac performance. It is also more sensitive than other modalities, such as exercise treadmill testing, for detecting multi-vessel coronary artery disease.
Given the limitations of Holter monitoring, stress echocardiography offers enhanced diagnostic accuracy and is particularly valuable for:
Syncope of Unclear Etiology: When the cause of fainting episodes remains undetermined.
Ventricular Arrhythmia: In patients with suspected or known ventricular arrhythmias.
Symptoms of Ischemic Equivalent: If symptoms suggestive of ischemia continue despite normal resting ECG and Holter monitoring results.
Possible Acute Coronary Syndrome (ACS): When patients present with symptoms consistent with ACS but have non-diagnostic ECG findings.
(Source: Standards for Provision of Echocardiography in Ontario, 2021)
For a comprehensive list of stress echocardiography indications and additional information about stress echo modalities, including contrast stress echocardiography, please visit our "For Doctors: Stress Echo" section.
The Holter report is meticulously analyzed by a cardiologist. A detailed report, including conclusions and clinical recommendations, is sent directly to the referring physician. This ensures that patients receive timely and accurate follow-up care.
To refer a patient for Holter monitoring, Stress Echocardiography, or any other diagnostic modality, please download the Requisition Form and fax it to our Requisition Processing Centre at 647-351-6648.
Care for Your Heart