[USE BULLETS INSTEAD OF NUMBERS IN THE SHORT LIST BELOW AND INDENT EACH LINE]
The purpose of this chapter is to demonstrate the usefulness of the body surface electrocardiogram in determining the etiology heart murmurs and their hemodynamic significance. Heart murmurs are the result of turbulent blood flow across heart valves, intracardiac defects or vascular abnormalities. Frequently, the abnormality causing the heart murmur is also associated with ventricular hypertrophy or dilatation, intraventricular conduction disturbances or cardiac arrhythmias. The correlation of these electrocardiographic changes with the characteristics of the heart murmur, such as its location, intensity, and radiation permits a more accurate diagnosis of the abnormality causing the murmur and a more precise analysis of its hemodynamic significance. For instance, the association of a systolic heart murmur with either left or right ventricular hypertrophy would indicate that the lesion responsible for the murmur had caused a pressure or volume overload of the involved ventricle and this information would contribute to the correct diagnosis of the lesion responsible for the murmur and a more accurate assessment of its severity. In this chapter, we will present examples of heart murmurs and the associated electrocardiograms. The goals for the reader are threefold:
1) To interpret the electrocardiogram
2) To diagnose the abnormality responsible for the heart murmur.
3) To predict the hemodynamic effect of the abnormality
The murmurs and phonocardiographic recordings are reproduced with permission from he CD-Rom by Criley, Criley and Zalace: The Physiological Origins of Heart Sounds and Murmurs; Lippencott-Raven, 1997