Electrocardiogram (ECG) remains the cornerstone of cardiovascular assessment, offering an inexpensive yet powerful tool for analyzing the heart's electrical activity.
This summarizes the key insights shared during a masterclass on ECG interpretation at the Philippine Heart Association-Philippine College of Cardiology (PHA-PCC) 55th Annual Convention and Scientific Meeting held at the Edsa Shangri-La on May 29, 2025, focusing on foundational and advanced ECG reading techniques.
Session 1: Fundamental ECG Interpretation & Confirmation
Dr. Jennifer Jeanne Vicera highlighted the common ECG reading pitfalls. She emphasized the critical role of reader competency, noting that a significant percentage of ECG interpretations contain clinically meaningful errors, some leading to inappropriate management decisions. Error rates were shown to be higher among non-cardiologists, while more errors (up to 40%) were also observed among medical professionals.
She stressed the need for rigorous training and standardized interpretation of protocols. Technical issues were also addressed, including artifacts caused by patient movement, poorly secured electrodes, and external interference.
Dr. Vicera demonstrated how such artifacts can mimic life-threatening arrhythmias or obscure critical ST-segment shifts. Electrode misplacement, particularly left and right arm reversal, was identified as a frequent source of error. They are often misinterpreted by the machine's software. This session explored false myocardial infarction reporting and computer errors that either masked or created diagnostic clues.
Dr. Vicera stressed, “Do not forget the basic rhythm.” Understanding basic rhythms is important reference point for interpretation. This helps caution against over-reliance on automated analysis and urges careful attention to detail. Specifically emphasizing the importance of not missing the T-wave when assessing arrhythmia.
Dr. Jose Antonio Bautista further elucidated the importance of confirming ECG findings. He highlighted the use of Cardiac MRI (CMR) as a classic standard for validating ECG-based diagnoses, particularly in cases of ventricular hypertrophy.
He also discussed various diagnostic criteria for left ventricular hypertrophy (LVH), emphasizing that voltage criteria should be supplemented by imaging studies and consideration of the patient’s comorbidities. The Cornell criteria, with its correlation to CMR, BSA, and sex, was highlighted for its predictive value regarding mortality and major adverse cardiovascular events (MACE). Both Drs. Vicera and Bautista underscored the limitations of even sophisticated ECG interpretation software, stressing the irreplaceable role of experienced medical judgment in accurate diagnosis. Bautista emphasized that while AI-assisted ECG interpretations are helpful, the "best AI is still you," highlighting the enduring need for human expertise and critical thinking.
Session 2: Advanced ECG Applications in Complex Scenarios
Dr. Jhobeleen De Leon presented challenging ECG cases illustrating the complexities of interpreting ECGs in patients with pacemakers, post-stress testing, and even scenarios alerted by smartwatches. The panel, including Dr. Paul Quetua, Dr. Erdie Fadreguilan, and Dr. Michael-Joseph Agbayani, analyzed three cases of patients over 61 years old.
The first case involved a 73-year-old female with a dual-chamber pacemaker. It presented with ectopic atrial rhythm, intermittent ventricular paced beats, and lead dislodgement thus illustrating the challenges in interpreting paced rhythms. Dr. De Leon said, “The pacemaker failed to sense.”
The second case was a 61-year-old male who developed sinus tachycardia with left bundle branch aberrancy during a treadmill stress test.
The third case featured a 65-year-old male with a history of valvular heart disease and an implantable cardioverter-defibrillator (ICD), presenting with atrial tachycardia and 2:1 ventricular tracking. It demonstrated the complexities of interpreting ECGs in patients with multiple devices. These presentations emphasized the importance of recognizing pacing artifacts, differentiating between pacemaker-induced rhythms and intrinsic cardiac activity, and understanding the implications of pacemaker malfunction, such as undersensing and asynchronous pacing. A final case highlighted the clinical utility of smartwatch alerts in detecting critical arrhythmias like complete heart block. The patient's condition ultimately leads to necessary hospitalization. The session concluded by emphasizing the importance of recognizing pacing artifacts, the distance between pacing spikes, potential lead switching, and the implications of pacemaker failure to sense, ultimately driving home the necessity for astute clinical judgment in interpreting complex ECGs.
Fr. L: Drs. Jennifer Jeanne Vicera, Jose Antonio Bautista and Michael-Joseph Agbayani
