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Measurement of Phasic Scapular and Intercostal Collateral Arterial Blood Velocity in Coarctation of the Aorta
GRAPHIC TECHNIQUES IN CARDIOLOGY Measurement of Phasic Scapular and Intercostal Collateral Arterial Blood Velocity in Coarctation of the Aorta* Alberto Benchimol, M.D., F.G.G.P., Jose Baldi, M.D., and Kenneth B. Desser, M.D.
Dilated tortuous collateral vessels of the axillae, back and sternum are well known clinical hallmarks in patients with coarctation of the aorta.' The subclavian, intercostal, internal mammary, musculophrenic, superior epigastric, transverse cervical, scapular and lateral thoracic arteries-all participate in channeling a more adequate blood flow to the lower part of the body in subjects with this disease." Pulsating collateral vessels are usually not visible in children with aortic coarctation but occasionally they may be observed around the scapular areas." We report here the measurement of such collateral arterial blood flow velocity by means of the external Doppler flowmeter probe. The use of this device for obtaining transcutaneous phasic arterial blood velocity in selected normal and pathologic states has been previously described in detail." Figure 1 shows simultaneously recorded lead 2 of the electrocardiogram, external pulse recordings and posterior thoracic collateral blood flow velocity in a nine-year-old boy with coarctation of the aorta. When the patient leaned forward in a sitting position, abnormal pulsations were palpated around the scapular regions. The outstanding characteristic °From the Institute for Cardiovascular Diseases, Good Samaritan Hospital, Phoenix, Arizona Supported in part by the Nichols' Memorial Fund. Reprint requests: Dr. Benchimol, Good Samaritan Hospital, Phoenix 85006 FIGURE 1 (right). Panel A: Simultaneous lead 2 of the electrocardiogram (L II) external left radial pulse tracing and collateral blood How velocity measured at the inner border of the left scapula. Note the large diastolic component of the How velocity waveform. Panel B: Simultaneous lead 2 of the electrocardiogram (L II) external jugular venous pulse tracing ( JVT) and collateral arterial blood velocity at the eighth intercostal space of the posterior thorax. Observe the marked increase of diastolic How velocity, which almost achieves systolic levels. Panel C: Simultaneous lead 2 of the electrocardiogram and flow velocity recorded at the ninth posterior intercostal space. There is no recordable flow velocity.
CHEST, VOL. 63, NO.6, JUNE, 1973
of phasic blood velocity as demonstrated in Figure I, panel A and panel B, was the large diastolic flow velocity fraction. Peak diastolic flow velocity at• COARCT. of AORTA
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tained levels which were at least 50 percent of peak systolic values. Such significant diastolic flow velocity has not been seen in the peripheral arterial recordings of more than 1,000 subjects investigated with the transcutaneous Doppler flowmeter. Aortic, left subclavian and intercostal volumetric blood flow has been measured in a few anesthetized human subjects during operative repair of coarctation of the aorta." Phasic flow patterns in vessels arising from the proximal segment of the coarcted aorta are characterized by an increased degree of forward flow during diastole." Interestingly, intercostal arterial blood flows toward the aorta under these circumstances.! It has been proposed that the amplitude of pulsation in these collateral intercostal arteries results in the well known roentgenologic sign of "rib notching."6 Our findings, obtained with the external Doppler probe in an intact conscious subject, confirm the increase of diastolic flow amplitude noted with direct flow measurement with the use of the electromagnetic flowmeter. It is possible that a fraction of this increased diastolic blood velocity is reverse in nature, and further study is needed to explore this possibility. In conclusion, the external Doppler flow velocity
BENCHIMOL, BALDI, DESSER
probe is a useful method for characterizing collateral blood flow in subjects with coarctation of the aorta. ACKNOWLEDGMENTS: We wish to acknowledge the technical assistance of Nancy Copeland, RN, Carole Crevier, Larry Kuriger, Sydney Peebles, Sharon Squire and Les Zendle. REFERENCES
1 Friedberg CK: Diseases of the Heart. (3rd ed ). Philadelphia, W. B. Saunders Company, 1966, p 1275 2 Keith JD, Rowe RD, Vlad P: Heart Disease in Infancy and Childhood. (2nd ed) New York, Macmillan Company, 1967, p 218-221 3 Franklin DL, Schlegel W, Rushmer RF: Blood flow measured by Doppler frequency shift of back-scattered ultrasound. Science 134:564-565, 1961 4 Benchimol A, Pedraza A, Brener L, et al: Transcutaneous measurement of arterial flow velocity with a Doppler flowmeter in normal subjects and patients with cardiac dysfunction. Chest 57:69-78,1970 5 Schenk WG Ir, McDonald KE, Andersen MN: Blood flow measurements in human coarctation. Studies on descending aorta and left subclavian and intercostal arteries before and after excision with repair. J Thorac Cardiovasc Surg 50:2630, 1965 6 Gooding CA, Glickman MG, Suydam MJ: Fate of rib notching after correction of aortic coarctation. Am J Roentgen 106:21-23, 1969
CHEST, VOL. 63, NO.6, JUNE, 1973
Dilated tortuous collateral vessels of the axillae, back and sternum are well known clinical hallmarks in patients with coarctation of the aorta.' The subclavian, intercostal, internal mammary, musculophrenic, superior epigastric, transverse cervical, scapular and lateral thoracic arteries-all participate in channeling a more adequate blood flow to the lower part of the body in subjects with this disease." Pulsating collateral vessels are usually not visible in children with aortic coarctation but occasionally they may be observed around the scapular areas." We report here the measurement of such collateral arterial blood flow velocity by means of the external Doppler flowmeter probe. The use of this device for obtaining transcutaneous phasic arterial blood velocity in selected normal and pathologic states has been previously described in detail." Figure 1 shows simultaneously recorded lead 2 of the electrocardiogram, external pulse recordings and posterior thoracic collateral blood flow velocity in a nine-year-old boy with coarctation of the aorta. When the patient leaned forward in a sitting position, abnormal pulsations were palpated around the scapular regions. The outstanding characteristic °From the Institute for Cardiovascular Diseases, Good Samaritan Hospital, Phoenix, Arizona Supported in part by the Nichols' Memorial Fund. Reprint requests: Dr. Benchimol, Good Samaritan Hospital, Phoenix 85006 FIGURE 1 (right). Panel A: Simultaneous lead 2 of the electrocardiogram (L II) external left radial pulse tracing and collateral blood How velocity measured at the inner border of the left scapula. Note the large diastolic component of the How velocity waveform. Panel B: Simultaneous lead 2 of the electrocardiogram (L II) external jugular venous pulse tracing ( JVT) and collateral arterial blood velocity at the eighth intercostal space of the posterior thorax. Observe the marked increase of diastolic How velocity, which almost achieves systolic levels. Panel C: Simultaneous lead 2 of the electrocardiogram and flow velocity recorded at the ninth posterior intercostal space. There is no recordable flow velocity.
CHEST, VOL. 63, NO.6, JUNE, 1973
of phasic blood velocity as demonstrated in Figure I, panel A and panel B, was the large diastolic flow velocity fraction. Peak diastolic flow velocity at• COARCT. of AORTA
8th INTERCOSTAL SPACE POST CHEST
C.
LII
1IIIIIIIII,!'IIIIIIIIII!I'llllllI1111'IIIII"IIIII!III'III'llllllllll!! 9th INTERCOSAL SPACE
1015
1016
tained levels which were at least 50 percent of peak systolic values. Such significant diastolic flow velocity has not been seen in the peripheral arterial recordings of more than 1,000 subjects investigated with the transcutaneous Doppler flowmeter. Aortic, left subclavian and intercostal volumetric blood flow has been measured in a few anesthetized human subjects during operative repair of coarctation of the aorta." Phasic flow patterns in vessels arising from the proximal segment of the coarcted aorta are characterized by an increased degree of forward flow during diastole." Interestingly, intercostal arterial blood flows toward the aorta under these circumstances.! It has been proposed that the amplitude of pulsation in these collateral intercostal arteries results in the well known roentgenologic sign of "rib notching."6 Our findings, obtained with the external Doppler probe in an intact conscious subject, confirm the increase of diastolic flow amplitude noted with direct flow measurement with the use of the electromagnetic flowmeter. It is possible that a fraction of this increased diastolic blood velocity is reverse in nature, and further study is needed to explore this possibility. In conclusion, the external Doppler flow velocity
BENCHIMOL, BALDI, DESSER
probe is a useful method for characterizing collateral blood flow in subjects with coarctation of the aorta. ACKNOWLEDGMENTS: We wish to acknowledge the technical assistance of Nancy Copeland, RN, Carole Crevier, Larry Kuriger, Sydney Peebles, Sharon Squire and Les Zendle. REFERENCES
1 Friedberg CK: Diseases of the Heart. (3rd ed ). Philadelphia, W. B. Saunders Company, 1966, p 1275 2 Keith JD, Rowe RD, Vlad P: Heart Disease in Infancy and Childhood. (2nd ed) New York, Macmillan Company, 1967, p 218-221 3 Franklin DL, Schlegel W, Rushmer RF: Blood flow measured by Doppler frequency shift of back-scattered ultrasound. Science 134:564-565, 1961 4 Benchimol A, Pedraza A, Brener L, et al: Transcutaneous measurement of arterial flow velocity with a Doppler flowmeter in normal subjects and patients with cardiac dysfunction. Chest 57:69-78,1970 5 Schenk WG Ir, McDonald KE, Andersen MN: Blood flow measurements in human coarctation. Studies on descending aorta and left subclavian and intercostal arteries before and after excision with repair. J Thorac Cardiovasc Surg 50:2630, 1965 6 Gooding CA, Glickman MG, Suydam MJ: Fate of rib notching after correction of aortic coarctation. Am J Roentgen 106:21-23, 1969
CHEST, VOL. 63, NO.6, JUNE, 1973