gm for the high sounds (26:92). Interpretation of the sounds requires a detailed knowledge of the normal heart sound (7:234-235), abnormal sounds (7:235-244), the effects of artifacts such as pacemakers, catheters and artificial valves (7:244-248), and cardiac murmurs (7:248-263).
Blood pressure, measured as the force exerted on the walls of the blood vessels at systole and diastole respectively, is determined by momentarily occluding the arm artery using an inflatable cuff and then releasing the pressure and listening for the first (systolic) "thump" and the second (diastolic) "thump" with a stethoscope. Measurement of pressure at these points is read off a mercury column pressure scale that is supported by the same air column that is pumped into the cuff (17:151). Average adult blood pressure is 120/80, and it is now generally agreed that pressure measurements consistently above 140/90 are indicative of hypertension (17:152).
The standard chest Roentgenogram (X-ray) is a basic first test that routinely follows the physical examination. It is painless, fast, inexpensive, and virtually risk-free since such small amounts of radiation are employed in modern procedures (although it may be contra-indicated for small children and pregnant women) (31:117). The patient stands with sustained inspiration, usually with anterior chest facing the film and X-ray source six feet behind (although the source may be eight or 10 feet behind, and care must be taken in comparing heart size in serial films) (23:375). Three specific categories of observations should be addressed to get maximum information from standard chest Roentgenograms: first, cardiac size compared to chest size and, if possible, sizes of specific chambers and great vessels, as well as their locations and configurations; second, calcium deposits in various parts of the heart, coronary arteries, and pericardium; and third, pulmonary function indicators such as increase or d...