Initial clinical results using intracardiac electrogram monitoring to detect and alert patients during coronary
Tim A Fischell1, David R Fischell, Alvaro Avezum
1Borgess Heart Institute, Kalamazoo, Michigan, USA.
Insights
Intracardiac ST-segment monitoring can alert high-risk patients to acute coronary events, reducing critical delays in seeking medical evaluation. This technology shows promise for early detection of thrombotic occlusions.
Area of Science:
- Cardiology
- Biomedical Engineering
- Medical Devices
Background:
- Delays in seeking medical attention for acute myocardial infarction persist, despite improvements in emergency response times.
- Early detection of acute coronary syndromes is crucial for timely intervention and improved patient outcomes.
Purpose of the Study:
- To evaluate the clinical utility of intracardiac ST-segment monitoring for early detection of thrombotic coronary occlusion in ambulatory patients.
- To assess the effectiveness of patient alerting systems in reducing symptom-to-door times.
Main Methods:
- Intracardiac ST-segment monitoring was implemented in 37 high-risk patients using a pacemaker lead.
- Continuous evaluation of ST segments identified significant shifts indicative of ischemic events.
Main Results:
- Four patients experienced ST-segment shifts (≥3 SDs) correlating with confirmed thrombotic coronary occlusion or ruptured plaque.
- The median alarm-to-door time was 19.5 minutes, significantly reducing delays in medical evaluation.
- Four patients were alerted for demand-related ischemia, and two false-positive alarms occurred.
Conclusions:
- Intracardiac ST-segment shifts exceeding 3 SDs may serve as a sensitive and specific marker for thrombotic coronary occlusion.
- Patient alerting systems facilitate prompt medical attention, particularly for high-risk individuals with recurrent coronary syndromes.
Objectives:
We report the first clinical studies of intracardiac ST-segment monitoring in ambulatory humans to alert them to significant ST-segment shifts associated with thrombotic occlusion.
Background:
Despite improvements in door-to-balloon times, delays in symptom-to-door times of 2 to 3 h remain. Early alerting of the presence of acute myocardial infarction could prompt patients to seek immediate medical evaluation.
Methods:
Intracardiac monitoring was performed in 37 patients at high risk for acute coronary syndromes. The implanted monitor continuously evaluated the patients' ST segments sensed from a conventional pacemaker right ventricle apical lead, and alerted patients to detected ischemic events.
Results:
During follow-up (median 1.52 years, range 126 to 974 days), 4 patients had ST-segment changes of ≥3 SDs of their normal daily range, in the absence of an elevated heart rate. This in combination with immediate hospital monitoring led to angiogram and/or intravascular ultrasonography, which confirmed thrombotic coronary occlusion/ruptured plaque. The median alarm-to-door time was 19.5 min (6, 18, 21, and 60 min, respectively). Alerting for demand-related ischemia at elevated heart rates, reflective of flow-limiting coronary obstructions, occurred in 4 patients. There were 2 false-positive ischemia alarms related to arrhythmias, and 1 alarm due to a programming error that did not prompt cardiac catheterization.
Conclusions:
Shifts exceeding 3 SD from a patient's daily intracardiac ST-segment range may be a sensitive/specific marker for thrombotic coronary occlusion. Patient alerting was associated with a median alert-to-door time of 19.5 min for patients at high risk of recurrent coronary syndromes who typically present with 2- to 3-h delays.
Related Concept Videos
01:30Pulse rhythm
Conversely, an irregular pulse pattern is termed dysrhythmia, stemming from disruptions in cardiac muscle...
01:30Acute Coronary Syndrome III: Diagnostic Studies
01:29Electrocardiogram
Three major waveforms are present in a typical ECG recording: the P wave, the QRS complex, and the T...
01:30Acute Coronary Syndrome I: Introduction
01:25Imaging Studies for Cardiovascular System VI: Calcium -Scoring CT
01:19Acute Coronary Syndrome II: Pathophysiology and Clinical Manifestations