John L. Gartlan

New method to measure phasic coronary blood velocity in man

Radio telemetry of phasic coronary artery blood velocity was described in 45 patients using a Doppler ultrasonic catheter flowmeter system. The influence of major vessel disease, respiration, cardiac arrhythmias, and nitroglycerin was examined. The coronary blood velocity wave form was characterized by a major diastolic wave representing maximum acceleration of blood during ventricular diastole. The systolic fraction of coronary blood velocity was normally less than 15 per cent of the diastolic component. There was no appreciable difference between the right and left coronary artery blood velocity curves. In one patient with severe obstructive lesion of the right coronary artery, the blood velocity profile was continuous throughout the cardiac cycle due to a marked increase in the systolic component. The importance of cycle length in determining the magnitude of peak diastolic blood velocity was exemplified in patients with tachycardia and extrasystoles. Administration of nitroglycerin resulted in a 10 to 15 per cent increase in both systolic and diastolic fractions in 46 patients. Although more experience with this technique is needed, it appears that this approach is useful in determining instantaneous, phasic coronary blood velocity from unexposed coronary arteries in conscious, unanesthetized man.

Bidirectional blood flow velocity in the cardiac chambers and great vessels studied with the Doppler ultrasonic flowmeter

Abstract Utilizing the bidirectional Doppler flowmeter catheter system, phasic forward and reverse flow velocity was measured in the cardiac chambers and great vessels of man. Recordings of right atrial, right ventricular and aortic flow velocity are characterized by a small reverse flow velocity component, usually occurring during early diastole, followed by a large forward systolic wave. Blood flow velocity in the left ventricular outflow tract and pulmonary artery is forward with negligible or no reverse flow. Ventricular extrasystoles and ventricular tachycardia result in diminished systolic and enhanced retrograde aortic and right ventricular flow velocity, possibly based on valvular incompetence. Aortic regurgitation and tricuspid insufficiency can be identified by their characteristic diastolic and systolic reverse flow velocity patterns. Patients with an increase in right atrial pressure, regardless of its etiology, manifest significant reverse flow velocity toward the caval system. We conclude that this technic is a valuable method for measuring bidirectional flow velocity under normal and pathologic conditions.

Telemetry of arterial flow in man with a Doppler ultrasonic flowmeter

Abstract 1. 1. Transcutaneous measurements of brachial artery flow velocity with the Doppler ultrasonic flowmeter were made in 82 subjects, of whom 24 were normal and 58 had heart disease. 2. 2. Aortic stenosis was associated with low peak flow velocity, prolonged ascending limb of the primary wave and decreased retrograde wave. Aortic insufficiency was recognized by the presence of a large secondary wave thought to represent retrograde flow. Subaortic stenosis altered the flow waveform in a characteristic manner. 3. 3. The technic was also found to be useful in the study of cardiac arrhythmias, Valsalva maneuvers and in the study of drugs with primary effect on the peripheral circulation. 4. 4. Although more experience is needed with its use in man, it appears that it may become a useful technic for monitoring patients in intensive care units.

The Valsalva Maneuver and Coronary Arterial Blood Flow Velocity: Studies in Man

Abstract Effects of the Valsalva maneuver on left coronary blood flow velocity were assessed in 15 patients with the Doppler catheter tip flowmeter. Straining against a closed glottis induced a dec...

Measurement of phasic carotid artery flow velocity in man

The flow velocity pattern in the common and internal carotid artery is described in seventeen patients using the catheter tip Doppler ultrasonic flowmeter telemetry system. The normal flow velocity pattern in the internal carotid arteries is pulsatile; it is characterized by a major systolic wave which occurs during ventricular systole, representing forward flow. The flow velocity pattern in the internal carotid artery, although phasic, is continuous throughout the cardiac cycle. Ventricular tachycardia results in marked reduction in carotid artery flow velocity, with variation in beat to beat flow velocity. With atrial fibrillation, there is significant variation in beat to beat peak flow velocity, and this is quite pronounced at a rapid heart rate. These variations have a direct correlation with the cycle length and emphasize the importance of diastolic filling time. This device may be used to study instantaneous phasic carotid artery flow velocity in conscious, unanesthetized man without the need for vessel exposure, and has potential value in the study of obstructive disease of the carotid arteries in patients with cerebral vascular insufficiency.

Phasic Coronary Arterial Flow Velocity During Arrhythmias in Man

Abstract The influence of cardiac arrhythmias on coronary arterial flow velocity studied by means of a Doppler catheter flowmeter system is described in 47 patients. The arrhythmias examined included atrial and ventricular extrasystoles, atrial fibrillation, pacemaker-induced atrial tachycardia, paroxysmal atrial tachycardia, ventricular tachycardia, Wenckebach second degree atrioventricular block and complete heart block. In atrial and, less frequently, in ventricular extrasystolic beats, peak coronary arterial flow velocity did not change significantly when the preceding R-R interval was greater than 0.50 second. However, when this interval was shorter than 0.50 second, a proportional decrease in peak coronary arterial flow velocity occurred. Variations in beat to beat coronary arterial flow velocity were seen uniformly in patients with atrial fibrillation. However, there was no correlation between peak coronary arterial flow velocity and the preceding R-R interval; in addition, no correlation was found between peak coronary arterial flow velocity and the same cycle length. In pacemaker-induced atrial tachycardia, decreased peaked coronary arterial flow velocity was observed at pacing rates greater than 140/min. In 1 patient with paroxysmal atrial tachycardia with an atrial rate of 200/min, there was a marked decrease and irregularity in coronary arterial flow velocity. The more abrupt decrease in flow velocity occurred in ventricular tachycardia. In Wenckebach second degree atrioventricular block, no measurable coronary arterial flow velocity was observed in the cycle encompassed by the dropped beat. However, the total area under the velocity curve was greater in the pre-dropped atrial beat than in other beats. In patients with complete heart block, the systolic component of flow velocity was greater than in patients in sinus rhythm.

Left ventricular blood flow velocity in man studied with the Doppler ultrasonic flowmeter

Abstract Left ventricular blood flow velocity was recorded in 32 conscious human subjects with the Doppler ultrasonic flowmeter catheter. There are three major left ventricular flow velocity patterns in man: (1) Inflow tract blood velocity is characterized by a predominant diastolic wave related to left ventricular filling succeeded by a smaller systolic component, (2) Midcavity blood flow velocity is triphasic in nature, and (3) Outflow tract blood velocity is manifested by a major systolic wave, resulting from left ventricular ejection. These flow velocity wave-forms parallel the major hemodynamic events occurring at each anatomic site. It is concluded that such study is of value for characterizing blood velocity in the left ventricle of conscious man.

Effects of amyl nitrite on coronary arterial blood flow velocity in man

Abstract Instantaneous coronary arterial phasic blood flow velocity was measured in 21 patients (8 with coronary artery disease) after amyl nitrite inhalation. Measurement was made with use of a Doppler ultrasonic flowmeter catheter positioned at the ostia of the coronary arteries. In all cases, there was an appreciable increase in diastolic coronary arterial phasic blood flow velocity within 10 seconds. Flow velocity increased from 50 to 216 percent over control values after administration of amyl nitrite. Subjects with marked obstructive coronary artery disease had decreased peak coronary arterial phasic blood flow velocity responses when compared with control subjects. Atrial pacing to heart rates attained with amyl nitrite alone resulted in no appreciable increase or decrease in coronary arterial phasic blood flow velocity, thus showing that increase in the latter was not dependent on this action of the drug. Furthermore, increase occurred before appearance of the arterial hypotensive effect of amyl nitrite. The presence of an increase in coronary arterial phasic blood flow velocity after administration of a drug with demonstrable coronary vasodilating action strongly suggests that one of the important attributes of nitrites is their ability to increase coronary arterial blood flow.

Radiotelemetry of phasic right ventricular blood velocity in man

Abstract Right ventricular flow velocity in the outflow tract of the right ventricle in 11 normal subjects and in 45 patients with heart disease was studied by radiotelemetry using a Doppler ultrasonic catheter flowmeter telemetry system. The influence of respiration, Valsalva maneuver and cardiac arrhythmias was examined. The right ventricular blood velocity in normal subjects was characterized by a major high frequency systolic wave representing acceleration of blood due to right ventricular ejection. The ejection pattern indicated that the rate of blood velocity was fast and of short duration. Inspiration resulted in an immediate increase in the peak right ventricular blood velocity; expiration caused an immediate decrease. The Valsalva maneuver in normal subjects resulted in an immediate decrease in velocity persisting throughout the maneuver with slight overshoot upon release of the maneuver. The influence of extrasystoles on the blood velocity was dependent on the time of occurrence of these extrasystoles. The shorter the interval between the extrasystoles and the preceding beat, the less the peak blood velocity of the extrasystolic beat and the greater the increase in postextrasystolic augmentation. Variation in beat to beat blood velocity occurred with regularity in patients with atrial fibrillation, thus emphasizing the importance of cycle length. Ventricular tachycardia was accompanied by a rapid and marked decrease of the right ventricular blood velocity which persisted for several seconds during this arrhythmia. This technique is useful in the study of (1) instantaneous phasic right ventricular blood velocity in conscious, unanesthetized man and (2) abnormalities of right heart dynamics in health and disease states.

Right atrial flow velocity in patients with atrial septal defect

Abstract Right atrial flow velocity was measured with the Doppler catheter connected to the Doppler ultrasonic flowmeter telemetry system in 6 patients with a secundum type of atrial septal defect. Fourteen normal subjects formed the control group. Right atrial flow velocity in normal subjects was phasic but continuous throughout the cardiac cycle. Although variations in the flow velocity wave form were frequently seen, three distinct waves were recorded. These waves have been designated as follows: S, during ventricular systole; D, during ventricular diastole; and A, during atrial contraction. In all patients with an atrial septal defect there was an increase in the amplitude of the A and D waves, but the S wave remained normal in size. These changes indicate that a large fraction of left to right shunt flow velocity through the septal defect occurred during early ventricular diastole and atrial contraction.