Praecordial Accelerometry: An Indirect Assessment of Left Ventricular Performance

Abstract

Abstract. 1. Praecordial acceleration was measured by a “pixie” strain gauge transducer in 14 dogs in whom an electromagnetic flow probe and pacing electrodes had been implanted. Peak acceleration of blood from the left ventricle (aortic max. dv/dt) was derived from the flow signal by differentiation. – 2. The amplitude of the major systolic complex (DE) of the praecordial accelerogram and aortic max. dv/dt were measured during stimulation of the heart with calcium gluconate and isoprenaline and depression of the heart with propranolol and halothane inhalation. – 3. Close linear correlations were found between the percentage change in the DE complex and the percentage change in aortic max. dv/dt during stimulation and depression of the heart. – 4. The amplitude of the DE complex was found to be sensitive to changes in left ventricular end‐diastolic pressure, systemic vascular resistance and increase in heart rate up to 150 beats per minute. – 5. It is concluded that changes in the amplitude of the DE complex of the praecordial accelerogram may be a useful index for non‐invasive assessment of changes in left ventricular function in the dog.

Non-invasive assessment of left ventricular response to Valsalva manoeuvre in normal and diabetic subjects using praecordial accelerocardiography.

“…In the diabetics with autonomic neuropathy there was a similar decrease in DE during the Valsalva manoeuvre but no significant increase above the control value occurred after release. Changes in DE have been shown to correlate closely with changes in the peak acceleration of blood flow in the ascending aorta in dogs during a wide range of manoeuvres (Reuben and Littler, 1973). Peak acceleration of aortic flow, in turn, is very sensitive to changes in left ventricular contractile state induced in dogs by coronary artery occlusion or the administration of various drugs (Noble et al, 1966;Nutter et al, 1971;Reuben and Littler, 1973).…”

“…Peak acceleration of aortic flow, in turn, is very sensitive to changes in left ventricular contractile state induced in dogs by coronary artery occlusion or the administration of various drugs (Noble et al, 1966;Nutter et al, 1971;Reuben and Littler, 1973). The praecordial accelerocardiogram therefore appears to be a useful non-invasive technique for detecting changes in left ventricular performance (Reuben and Littler, 1973).…”

“…Praecordial accelerocardiography is a useful noninvasive technique for detecting changes in peak acceleration of aortic blood flow, which itself is a sensitive measure of left ventricular performance (Reuben and Littler, 1973).…”

“…The praecordial accelerocardiogram transducer, which has been described in detail previously (Reuben and Littler, 1973;Hume et al, 1975), was attached by an adhesive disc to the chest wall overlying the fifth rib at a point medial to the apex beat. A simultaneous electrocardiogram was recorded with the accelerocardiogram on the second channel of an ultraviolet recorder.…”

Correlation between praecordial accelerocardiogram and left ventricular pressure.

“…The accelerocardiogram transducer, whose physical nostic cardiac catheterization after the collection of characteristics have been fully described (Bew et al, resting haemodynamic data but before angiographic 1971; Reuben and Littler, 1973), was attached to the studies. Beta-adrenergic blocking drugs were disconchest wall overlying the fifth rib internal to the apex tinued 72 hours before catheterization but all other drugs beat by means of an adhesive disc.…”