1. An echocardiographic diagnostic apparatus comprising pulse-echo ultrasonic means for insonifying the heart of a subject with successive pulses of ultrasonic wave energy synchronized with the heartbeat of said subject and then detecting echoes of said insonified heart of said subject, said detected echoes including those which when displayed on a cathode-ray-tube display appear as an M-wave, said M-wave having a waveform shape specifically determined by both the movement of said subject's heart as a whole and by the movement of the mitral valve within said subject's heart, said specifically-determined waveform of said M-wave including a first-occurring peak followed, in turn, by a valley and then by a second-occurring peak smaller in amplitude than said first-occurring peak; the combination therewith of an A-wave quantification indicator coupled to said pulse-echo ultrasonic means for measuring the difference in amplitude between said first and second peaks of said M-wave detected echoes and selectively deriving, in accordance with the value of said measured difference, an indication in a form that distinguishes subjects suffering from one of myocardial disease and hyperkinetic syndrome from normal subjects.
1. An echocardiographic diagnostic apparatus comprising pulse-echo ultrasonic means for insonifying the heart of a subject with successive pulses of ultrasonic wave energy synchronized with the heartbeat of said subject and then detecting echoes of said insonified heart of said subject, said detected echoes including those which when displayed on a cathode-ray-tube display appear as an M-wave, said M-wave having a waveform shape specifically determined by both the movement of said subject's heart as a whole and by the movement of the mitral valve within said subject's heart, said specifically-determined waveform of said M-wave including a first-occurring peak followed, in turn, by a valley and then by a second-occurring peak smaller in amplitude than said first-occurring peak; the combination therewith of an A-wave quantification indicator coupled to said pulse-echo ultrasonic means for measuring the difference in amplitude between said first and second peaks of said M-wave detected echoes and selectively deriving, in accordance with the value of said measured difference, an indication in a form that distinguishes subjects suffering from one of myocardial disease and hyperkinetic syndrome from normal subjects. 2. The apparatus defined in claim 1, wherein said pulse-echo ultrasonic means comprises adjustable time-delay gating means including a range gate adjustable to be open for a first time interval which includes the time of occurrence of said entire M-wave, an E gate adjustable to be open for a second time interval which includes said first peak but excludes said valley and said second peak of said M-wave, and an A gate adjustable to be open for a third time interval which includes said second peak but excludes said first peak and said valley of said M-wave, and wherein said indicator comprises a gated peak-detector and hold circuit including a storage capacitance, a reversible counter, an analog-to-digital converter coupled between said gated peak-detector and hold circuit and said counter to apply a count input to said counter in accordance with the magnitude of any signal stored in said capacitance, control means coupled to said reversible counter for effecting an UP count in response to the occurrence of said E gate and for effecting a DOWN count in response to the occurrence of said A gate, means for charging said storage capacitance only during said second time interval and during said third time interval and discharging said storage capacitance at the end of said second time interval and at the end of said third time interval, whereby the certain count registered in said reversible counter at the end of a predetermined integral number of one or more complete UP and DOWN cycles thereof is proportional to the difference between said first and second peaks, and output means responsive to said certain count for producing said display indication.