A comparison of coarctation resection and patch angioplasty using postexercise blood pressure measurements

Postexercise arm-to-leg blood pressure gradients were measured in 31 patients to determine the effectiveness of two surgical techniques for treating coarctation of the aorta. The arm-to-leg postexercise mean systolic blood pressure gradient was 29 mm Hg lower in 13 patients treated with Dacron patch angioplasty than in 18 patients whose coarctation was resected (p less than 0.01). Some patients with high postexercise gradients after coarctation resection had a reduced proximal aortic lumen by angiography. The results of this study indicate that Dacron patch angioplasty is the method of choice for effectively reducing postexercise systolic pressure gradients in patients with coarctation and hypoplasia of the aortic isthmus.     

Coarctation of aorta with complete aortic occlusion

Survival to advanced age is exceptional in patients with unrepaired aortic coarctation. We report the case of an 81-year-old man with aortic coarctation and total occlusion who was otherwise asymptomatic. Coarctation was suspected when a femoral-radial pulse delay was noted during his routine physical examination. A 70-mmHg systolic blood pressure gradient between the upper and lower extremities was detected. Subsequent magnetic resonance angiography, aortography, and coronary angiography revealed severe coarctation of the aorta, well-developed collateral vessels, and severe coronary artery disease. A staged percutaneous coronary intervention procedure was performed and the coarctation was managed conservatively with antihypertensive medication.     

Hemodynamic and hormonal abnormalities in canine aortic coarctation at rest and during exercise

This study was designed to determine the hemodynamic and hormonal consequences of aortic coarctation at rest and during treadmill exercise. Twelve normal adult dogs served as controls. In eight dogs coarctation was created within 1 week of birth by banding the aorta just proximal to the ductus ligament, thereby fixing luminal diameter at 1 to 2 mm. Studies were performed 18 months after operation. Vascular pressures were monitored proximal and distal to the coarctation, cardiac output and regional blood flow were evaluated with radioactive microspheres and blood samples were collected for determination of hormone levels and blood gases. At rest, systolic pressure in the proximal aorta was 130 +/- 12 mm Hg (mean +/- SD) in the control group and 167 +/- 16 mm Hg in dogs with coarctation (p less than 0.01). During exercise at a level that doubled heart rate and cardiac index, mean aortic pressure increased by 11 and 31% (p less than 0.01) in the control and the coarctation group, respectively. Mean distal aortic pressure increased by 8% during exercise in control dogs but decreased by 29% in dogs with coarctation. Exercise decreased flow to the kidneys and the large intestine in the coarctation group. Plasma norepinephrine concentrations were greater in the coarctation group than in control dogs at rest; during exercise, plasma norepinephrine, epinephrine and renin activity increased in both groups, but to a greater degree in the group with coarctation. These results confirm an abnormality in renal and gut perfusion in experimental coarctation and suggest that this may be related to a decline in perfusion pressure.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of aortic coarctation after surgical repair: role of magnetic resonance imaging and Doppler ultrasound.

OBJECTIVE--To compare the usefulness of magnetic resonance imaging (MRI) and Doppler ultrasound with that of cross sectional echocardiography and oscillometric blood pressure measurement for the evaluation of aortic coarctation after surgical repair. DESIGN--Prospective study. Aortic diameters measured by cross sectional echocardiography, MRI, and angiography (selected cases) and functional data determined by physical examination, oscillometric blood pressure measurement, and continuous wave Doppler. SETTING--Tertiary referral centre. PATIENTS--40 patients aged 2-28 years (mean 10.6 years) who had had surgical correction of aortic coarctation (mean follow up 5.7 years). RESULTS--In all patients MRI gave diameter measurements of the aortic arch and the thoracic aorta whereas in half of them cross sectional echocardiographic measurement of the isthmic region failed. The correlation coefficient for aortic diameters measured by MRI and angiography was 0.97 and that between MRI and echocardiography was 0.89. Peak velocities in the descending aorta correlated better with residual narrowing of the aortic isthmus or distal aortic arch or both than systolic blood pressure gradients between the upper and lower limbs. A peak velocity of < 2 m/s in the descending aorta during systole excluded important restenosis. Prolongation of anterograde blood flow during diastole always indicated a morphological abnormality--either important restenosis or aneurysmal dilatation. CONCLUSIONS--MRI was better than cross sectional echocardiography for imaging the aortic arch after coarctation repair and measuring its diameter. Peak velocity in the descending aorta correlated better with residual stenosis than did the systolic blood pressure gradient between the upper and lower limbs and this index could be used to indicate a need for MRI.     

A clinically masked normotensive aortic coarctation

A rare variety of aortic coarctation in which both the left subclavian and aberrant right subclavian arteries arose at the coarcted segment is described. Clinically this case was misleading since pulse volume and the blood pressure in all four limbs were equal and chest radiograph was lacking classical features of coarctation of aorta. Multi slice CT aortogram typically demonstrated the relationship of major aortic arch branches. Later he underwent balloon coarctoplasty and stenting with success. The literature relating to unusual coarctation is reviewed in brief     

Pressure wave reflection after successful balloon dilatation of aortic coarctation.

After successful surgical repair in patients with aortic coarctation, the early onset of cardiovascular diseases is an important subsequent complication and one of the causes is the enhanced aortic pressure wave reflection. Balloon angioplasty has become established as an effective alternative to surgery, but there have been no reports regarding pressure wave reflection after balloon dilatation in patients with aortic coarctation. A 29-year-old patient with aortic coarctation was admitted for angioplasty, which was performed successfully. Six months later, catheter examination demonstrated enhanced aortic pressure wave reflection, although there was no pressure difference. After balloon dilatation patients with aortic coarctation may be also at high risk for future cardiovascular diseases.     

Left cervical aortic arch with aortic coarctation and saccular aneurysm

Cervical aortic arch is a very rare malformation and is occasionally accompanied by other cardiovascular anomalies. A 48-year-old male patient had a left cervical aortic arch with aortic coarctation and saccular aneurysm distal to the coarcted segment. The major clinical manifestations were upper body hypertension with a 50-mmHg discrepancy between the upper and lower limbs and a loud continuous murmur in the upper chest and back. Magnetic resonance angiography successfully depicted the anomalous aorta, and the aortic coarctation and aneurysm were surgically resected and the thoracic aorta was reconstructed. The discrepancy in blood pressure diminished after the operation, but antihypertensive medication was continued to satisfactorily control the hypertension.     

Transcatheter double stent implantation for treatment of middle aortic coarctation syndrome

A 13‐year‐old boy presented with severe systemic hypertension. His upper limb blood pressure measured 190/100 mm Hg and lower limb blood pressure measured 98/64 mm Hg. The brachial pulses were bounding and femoral pulses were not palpable. Echocardiography and magnetic resonance angiography confirmed middle aortic syndrome. There was severe diffuse thoraco‐abdominal coarctation with continuous Doppler run‐off. Cardiac catheterization was undertaken and using a retrograde approach two Advanta V12 stents were implanted in the complex thoraco‐abdominal coarctation. The gradient across the coarctation was reduced from 80 to 40 mm Hg gradient with a significant improvement in the luminal diameter of the aorta. His upper limb blood pressure reduced to 142/78 mm Hg six weeks later. © 2013 Wiley Periodicals, Inc.     

Overall hemodynamic pattern in coarctation of the abdominal aorta in conscious rats

This study was designed to examine the total body hemodynamics of abdominal aortic coarctation hypertension. The study quantitates both regional and organ blood flow and resistance in conscious rats both above and below an experimentally produced coarctation. The experimental group consisted of 10 male Sprague-Dawley rats with a mean pressure gradient of 68 mm Hg across the coarctation. This experimental group was compared with a group of eight control rats with no pressure gradient. Flow measurements were made with radioactively labeled microspheres 4 weeks after aortic constriction. This aortic coarctation produced an increase in cardiac index (22%) and total peripheral resistance (19%). Blood flow through tissues proximal to the coarctation was not different from control; vascular resistance was increased (31%). Flow through the tissues distal to the coarctation was increased (16%); vascular resistance was decreased (-22%). The upper carcass, diaphragm, and brain were the tissues most representative of flow above the coarctation, and the lower carcass and large intestine were the tissues most representative of flow below the coarctation. Coarctation of the aorta produced cardiac hypertrophy and increased microsphere shunting to the lungs.     

Increased stiffness and persistent narrowing of the aorta after successful repair of coarctation of the aorta: relationship to left ventricular mass and blood pressure at rest and with exercise.

Fifteen children and adolescents who had repair of coarctation of the aorta before age 15, who were not hypertensive at rest, and who had resting arm-leg blood pressure gradients of less than 20 mm Hg underwent noninvasive evaluation of left ventricular structure and function, aortic stiffness, and residual coarctation as well as bicycle exercise testing. These results were compared with those in 15 age- and sex-matched control subjects. The mean resting age-related systolic blood pressure percentiles (63% versus 46%), transverse aortic stiffness measured by the elastic modulus (Ep) (42.1 versus 23.2 kPa), stiffness index beta (beta) (3.66 versus 2.17), echocardiographic left ventricular fractional shortening (0.42 versus 0.36), left ventricular mass index (99.3 versus 81.0 gm/m2), maximum exercise right arm systolic blood pressure (173 versus 156 mm Hg), and exercise arm-leg blood pressure gradient (35 versus 6 mm Hg) were significantly increased in the coarctectomy patients compared with controls. Univariate correlations in the coarctectomy group showed significant relationships of residual aortic narrowing with left ventricular mass index (r = 0.68, p less than 0.01) and resting systolic blood pressure percentile for age (r = 0.55, p less than 0.05). Residual aortic narrowing did not significantly correlate with aortic stiffness, resting blood pressure gradient, or exercise blood pressure gradient. Neither left ventricular mass index nor resting systolic blood pressure percentile significantly correlated with age of repair or years after repair. These results demonstrate persistent abnormalities in aortic stiffness and left ventricular mass and function after successful repair of coarctation of the aorta in childhood and adolescence.(ABSTRACT TRUNCATED AT 250 WORDS)     

Use of continuous wave Doppler ultrasound velocimetry to assess the severity of coarctation of the aorta by measurement of aortic flow velocities

Peak ascending and descending aortic blood flow velocities were measured using continuous wave Doppler ultrasound velocimetry in 30 children with coarctation or recoarctation of the aorta and in 13 control subjects. The results were compared with the arm to leg systolic blood pressure difference. The peak flow velocities in the descending aorta were significantly higher in the patients than in the control subjects and there was a close correlation with the systolic blood pressure gradient. Since there was no overlap of flow velocities between the patients and the control subjects the Doppler technique enables coarctation confidently to be excluded as well as demonstrating its presence and severity. The method is simple, rapid, independent of the condition of the aortic valve, and is applicable to neonates in whom the diagnosis of coarctation may otherwise be difficult. In older children it is useful for detecting recoarctation and following its progress, particularly in patients in whom a reliable estimate of the systolic blood pressure gradient cannot be obtained.     

Use of continuous wave Doppler ultrasound velocimetry to assess the severity of coarctation of the aorta by measurement of aortic flow velocities.

Peak ascending and descending aortic blood flow velocities were measured using continuous wave Doppler ultrasound velocimetry in 30 children with coarctation or recoarctation of the aorta and in 13 control subjects. The results were compared with the arm to leg systolic blood pressure difference. The peak flow velocities in the descending aorta were significantly higher in the patients than in the control subjects and there was a close correlation with the systolic blood pressure gradient. Since there was no overlap of flow velocities between the patients and the control subjects the Doppler technique enables coarctation confidently to be excluded as well as demonstrating its presence and severity. The method is simple, rapid, independent of the condition of the aortic valve, and is applicable to neonates in whom the diagnosis of coarctation may otherwise be difficult. In older children it is useful for detecting recoarctation and following its progress, particularly in patients in whom a reliable estimate of the systolic blood pressure gradient cannot be obtained.     

Asymptomatic severe aortic coarctation in an 80-year-old man

Survival to advanced age is exceptional in patients with unrepaired aortic coarctation. We report the case of a hypertensive 80-year-old man with coarctation of the aorta who was otherwise asymptomatic. Coarctation was suspected when a femoral-radial pulse delay was noted during his routine physical examination. A 25-mmHg systolic blood pressure gradient between the upper and lower extremities was detected. Subsequent magnetic resonance angiography, aortography, and coronary angiography revealed severe coarctation of the aorta, well-developed collateral vessels, and severe coronary artery disease that included the left main artery. Coronary artery bypass grafting was performed, and the coarctation was managed conservatively with antihypertensive medication. At the 1-year follow-up visit, the patient was still asymptomatic and maintained a normal blood pressure with medication.     

Right-sided aorta with atypical coarctation involving only the left subclavian artery. Hypertension

A case has been described of right-sided aorta with coarctation of the left subclavian artery. The diagnosis was made clinically and by ordinary x-ray film and then confirmed by angiocardiographic films.A small or absent left radial pulse in the presence of a hypertension in the right arm and a normal expected blood pressure in the lower extremities should lead to the consideration of the diagnosis of a localized coarctation of the left subclavian artery. Such causes as cervical rib, anomalous course of the left radial artery, tumors, and aortic aneurysm must first be investigated.With a localized coarctation of the left subclavian artery, just as with the typical coarctation of the aorta, a hypertension is usually present. It is probably a reflex mechanism originating from the nerves in the aortic arch and producing an increased vascular tone in all the extremities.Localized coarctation of the left subclavian artery frequently is discovered by accident. The patient presents no anatomic or physiologic defect in the left upper extremity except the small or absent left radial pulse. Hard work is quite compatible with the lesion.     

Long-term effects of balloon angioplasty on systemic hypertension in adolescent and adult patients with coarctation of the aorta.

AIMS: To define the long-term effect of balloon angioplasty of aortic coarctation on hypertension, in adolescent and adult patients. METHODS: Balloon angioplasty of discrete, native aortic coarctation was performed on 50 patients (34 male) aged 23+/-8 (mean+/-standard deviation) years. In 42 of these patients cardiac catheterization and angiography were repeated 1 year later, and on the basis of sphygmomanometric blood pressure determination at that time, they were divided into 31 patients (group A) with normalized blood pressure and 11 patients (group B) who still needed antihypertensive medication. Both groups were followed annually thereafter for 12-123 (66+/-37) months. RESULTS: Coarctation gradient values before, immediately after and 1 year after angioplasty were 69+/-24 mmHg, 12+/-8 mmHg (P<0.001) and 7+/-6 mmHg. The corresponding systolic blood pressure values were 165+/-17 mmHg, 128+/-12 mmHg (P<0.001) and 115+/-10 mmHg (P<0.001) in group A; 182+/-21 mmHg, 141+/-24 mmHg (P<0.001) and 134+/-18 mmHg (P<0.001) in group B. Echocardiographic left ventricular mass index before angioplasty and at follow-up was 130+/-31 g x m-2 and 105+/-23 g x m-2 in group A; 157+/-38 g x m-2 and 132+/-35 g x m-2 in group B (P<0.001 for both comparisons). CONCLUSION: Normalization of blood pressure without medication occurred in 74% of patients after angioplasty for aortic coarctation, with subsequent long-term regression of left ventricular hypertrophy. In comparison to reported surgical results, balloon angioplasty should be considered as first line treatment for native, discrete aortic coarctation in adolescent and adult patients.     

Predictors of aneurysmal formation after surgical correction of aortic coarctation

OBJECTIVES: We sought to identify the predictors of aneurysmal formation after surgical correction of aortic coarctation. BACKGROUND: In 9% of patients, aneurysms develop late after corrective surgery of coarctation of the aorta, with a 36% mortality rate if left untreated. However, the predictors of postsurgical aneurysmal formation are unknown. METHODS: Of 25 aortic aneurysms requiring corrective surgery 152 +/- 78 months after the initial coarctation repair, 8 were located in the ascending aorta (type A) and 17 at the site of previous repair (local type). Seventy-four patients without progression of the aortic diameter within 189 +/- 71 months after coarctation repair were used for categorical data analysis in an attempt to identify the predictors of postsurgical aneurysmal formation. RESULTS: Advanced age at coarctation repair (p = 0.004) and patch graft technique (p < 0.0005) independently predicted local aneurysmal formation. Type A aneurysm was univariately associated with the presence of a bicuspid aortic valve (p = 0.02), advanced age at coarctation repair (p = 0.044) and a high preoperative peak systolic pressure gradient of 74 +/- 21 mm Hg (p = 0.041). Conversely, multivariate analysis confirmed only the presence of a bicuspid aortic valve (p = 0.015) as an independent predictor of type A aneurysm. Receiver operating characteristic curve analysis revealed that 72% of patients with a postsurgical aneurysm had an operation at age 13.5 years or more, whereas 69% with no postsurgical aneurysm had an operation at a younger age. CONCLUSIONS: Use of the patch graft technique and late correction of coarctation can predict aneurysmal formation at the site of coarctation repair, although patients with a bicuspid aortic valve may be at risk for an aneurysm developing in the ascending aorta, particularly after late repair of aortic coarctation with high preoperative pressure gradients.     

Arterial pressure during exertion in patients operated on for aortic coarctation]

19 patients were studied after operation for coarctation of the aorta. The average age at operation was 13.7 years. Crafoord's operation was performed in 16 cases and in the other three an aortic patch was necessary. The average post-operative period was 4.7 years. 14 cases were classified as good results: normal femoral pulses and arterial blood pressure. The other 5 cases were considered as unsatisfactory: 2 mediocre results with normal arterial blood pressure but diminished femoral pulses and oscillometric indices; 3 poor results with hypertension at rest. On exercise with bicycle ergometry the following results were obtained: the systolic blood pressure rose in a comparable manner to that observed in normotensive individuals of the same age on exercise except in 2 cases. These two patients had an aortic patch and one had a residual intraaortic pressure gradient. The pronostic significance of these findings is not known. However the use of an aortic patch is often associated with abnormal blood pressures at rest or on exercise. The fact that the majority of patients operated for coarctation of the aorta have normal blood pressure profiles on exercise should be emphasised.     

Doppler ultrasound in the assessment of severity of coarctation of the aorta and interruption of the aortic arch.

Doppler ultrasound was used to investigate 48 infants and children (age 2 days-16 years, weight 1.0-58 kg) with aortic arch abnormalities. In only 38 of the 42 with an important coarctation was an increased blood flow velocity from the distal arch demonstrated. In three with interruption of the aortic arch an increased velocity recorded from the region of the distal arch was thought to represent ductal flow. There was little difference between the peak to peak and instantaneous maximum gradients in the 20 patients with important coarctation in whom direct pressure measurements both proximal and distal to the obstruction were made at catheterisation. There were poor agreements between Doppler and measured peak to peak and instantaneous gradients in the 17 patients found to have both an increased velocity and important coarctation. It is concluded that although an increased blood flow velocity in the distal arch is usually demonstrated in coarctation this may not occur with severe obstruction. Furthermore, the maximum velocity is not related to the anatomical severity of the obstruction and the Doppler estimate of pressure drop in coarctation may not even reliably predict that measured at catheterisation.     

Coarctation of the aorta

Coarctation of the aorta is an important, treatable cause of secondary hypertension. Its prevalence varies from 5% to 8% of all congenital heart defects. This condition is most often detected because of a murmur or hypertension found on routine examination. Delayed or absent femoral pulses and an arm/leg systolic blood pressure difference of 20 mm Hg or more in favor of the arms may be considered as evidence for aortic coarctation. The coarctation may be demonstrated on a suprasternal notch two-dimensional echocardiographic view along with increased Doppler flow velocities across the coarctation site. Cardiac catheterization reveals significant systolic pressure gradient (> 20 mm Hg) across the coarctation and angiography demonstrates the degree and type of aortic narrowing. Aortic obstruction may be relieved by surgery or by transcatheter techniques; the latter include balloon angioplasty and stent implantation. In the past, surgery has been used exclusively, but because of morbidity and complications associated with surgery, catheter techniques are increasingly used in the management of aortic coarctation. Balloon angioplasty in children and stents in adolescents and adults are becoming initial therapeutic options for management of coarctation. Studies evaluating long-term follow-up results of the interventional techniques are needed.     

Abnormal responses for blood pressure in children and adults with surgically corrected aortic coarctation

BACKGROUND: Despite successful surgical repair of aortic coarctation, life expectancy is reduced, and up to one-third of patients remain or become hypertensive. So as to characterize the responses for blood pressure, we have studied 55 patients with surgically repaired coarctation. Their mean age was 11.3 +/- 5.97 years. We documented maximal uptake of oxygen, anaerobic threshold, plasma renin activity and blood pressures during a Bruce protocol treadmill test. The velocity across the site of repair as imaged by cross-sectional echocardiography was measured before and after exercise. We measured the changes in heart rate and blood pressure subsequent to an infusion of 1 ug per kg of isoprenalin, monitoring blood pressure over 24 hours in all patients. RESULTS: When compared with 40 healthy age-matched controls, the patients with coarctation had a normal exercise capacity. Resting systolic blood pressures above the 95th percentile were present in 45% of the patients. Exercise-induced hypertension, and an elevation in the average systolic 24 hour blood pressures, were observed, but less frequently than elevated baseline values, suggesting that so-called white-coat" hypertension may be present in this population. Abnormal reactions and elevation of plasma renin activity were related to a history of paradoxical hypertension at the time of surgery. Attenuation of the circadian rhythm for blood pressure was a frequent finding, and may have implications in the development of long-term damage to end-organs. A high correlation was found between mean systolic blood pressure measured by 24 hour monitoring and left ventricular hypertrophy (r=0.65, p<0.05). CONCLUSIONS: Abnormalities in blood pressure occurred independently of significant mechanical obstruction. Despite successful surgical repair, abnormalities in the shape of the aortic arch, reduced sensitivity of baroreceptor reflexes, and neurohumoral factors may all contribute to the development of hypertension.