Abstract 18563: The Role of a Change in ECG Voltage on the Diagnosis and Prognosis in Cardiac Amyloidosis
Background: Low voltage on ECG may be caused by various medical conditions. In cardiac amyloidosis, low voltage in the limb leads is found in approximately 50% with AL and only 20-25% of ATTR, whether senile or familial. Despite not meeting low voltage criteria on ECG, a reduction of voltage over time may signify amyloid cardiomyopathy.
Methods: The electrocardiograms of consecutive patients at the time of a diagnosis of cardiac amyloidosis at our institution were analyzed. Patients with ventricular paced rhythms were excluded. An additional ECG at least one year prior to the diagnosis was also analyzed. The sum of voltage in all limb leads and the Sokolow voltage (S wave in V1 plus R wave in V5 or V6) index were calculated. Low limb voltage was defined as ≤ 5 mm in all limb leads and low precordial voltage as ≤ 10 mm in all precordial leads. A Cox proportional hazards model was used to assess the correlation between decreasing ECG voltage and 3 year mortality.
Results: A total of 338 patients (192 AL, 146 ATTR, age 68.7 +/- 12.1 years, obese 57%, HTN 54%) were identified. At the time of diagnosis, 167 patients (49.4%) met either low limb or low precordial voltage criteria. The limb lead voltage decreased in 63 of 73 patients (86.3%) and the Sokolow voltage decreased in 62 of 73 patients (84.9%). The mean overall decrease in limb lead voltage was 10.6 +/- 12.6 mm overall or 3.3 +/- 4.6 mm per year. The Sokolow voltage decreased 6.5 +/- 7.1 mm overall or 1.8 +/- 2.3 mm per year. On univariable analysis, the annualized decrease in Sokolow voltage showed a non-significant trend towards an increase in mortality.
Conclusion: A decrease in voltage on serial ECG’s is more prevalent than low voltage in cardiac amyloidosis. There is a trend towards increased mortality in patients who have a greater decrease in voltage over time. The evaluation of serial ECG’s for changes in voltage is important to recognize in the diagnosis of cardiac amyloidosis and may have prognostic value.
Author Disclosures: I. Bagh: None. B. Sperry: None. M. Vranian: None. M. Hanna: None.
- © 2015 by American Heart Association, Inc.