RESTING BODY SURFACE MAPS COMBINED WITH NITROGLYCERINE TEST MAY PREDICT ELEVATED
LEFT ATRIAL PRESSURE DUE TO EXERCISE INDUCED ISCHEMIA

T. Bauernfeind, M. Medvegy, G. Duray, E. Szűcs, A. Pintér, T. Borsányi, Krisztina Szakolczay,
I. Préda
Semmelweis Universitiy, 2nd Dept. of Cardiology

BACKGROUND

Abnormal left ventricular compliance and augmented left atrial pressure may manifest in signs of left atrial enlargement on the ECG. This sign can be more accentuated in inducible ischemia (positive exercise test), and may change after nitroglycerin administration.

METHOD

Based on the exercise ECG test, 61 patients with ischemic heart disease were divided into two groups: 30 patients had a positive test, and 31 patients had a negative test. The specified left atrial electrical potential values (SLAP) - sums of the greatest posterior maximum and the simultaneous anterior minimum – were examined with resting BSPM (using the Montreal system, 63 leads) before and 6 minutes after inhalation of 0.8 mg nitroglycerin aerosol.

RESULTS

We found a mean 29% decrease (one-sample analysis, p<0.0001) of the SLAP due to nitroglycerin effect in the group of positive exercise test. There was no significant change in the group with negative exercise test (+1%). The difference between the two groups was significant  (two-sample analysis p<0.0001). 

CONCLUSION

The significant decrease of the SLAP due to nitroglycerin effect refers to the positivity of the exercise test. Resting BSPM may provide a new method for the detection of exercise induced elevation in left atrial pressure.