Balloon valvuloplasty for pulmonic valve stenosis—two-year follow-up: Hemodynamic and doppler evaluation

The purpose of this investigation was to evaluate the efficacy, technique, and follow-up results of balloon dilation angioplasty for valvular pulmonary stenosis. Percutaneous dilation was performed on 63 patients with pulmonary stenosis (ages 3 months to 76 years, mean = 4.3 years). In 43 patients, a single balloon was used; in 20 patients two balloons were used simultaneously. The pressure gradient across the pulmonary valve was determined with right ventricular and main pulmonary artery catheters. Pressure gradients simultaneously were estimated by continuous wave Doppler (CWD) during catheterization. The peak systolic ejection gradient was obtained by both techniques both pre- and postangioplasty. There was excellent linear correlation between the simultaneous catheter pressure gradient and the pressure gradient estimated by Doppler (r = 0.99). Follow-up pressure gradient estimations by Doppler echocardiogram were obtained in 30 patients between 6 months and 30 months postcatheterization (mean = 13 months). The mean preangioplasty gradient of 64 mm Hg (range 30–160 mm Hg) was reduced to 22 mm Hg (range 2–31 mm Hg). A significant reduction of transvalvular gradient (52–95%, mean 68%) occurred in each patient. A linear correlation was found between the predilation gradient and the pressure gradient drop (r = 0.92). Mean follow-up gradient by Doppler was 20 mm Hg (range 0–31 mm Hg), and there was no significant difference between these gradients and the postdilation gradient. No important complications were noted. These data confirm that balloon dilation angioplasty for valvular pulmonary stenosis is safe and effective, and suggest that stenosis does not recur.     

Balloon dilation valvuloplasty of bioprosthetic valves in extracardiac conduits

Six patients, aged 8 to 20 years, with valved right ventricle to pulmonary artery conduits were catheterized for balloon dilation valvuloplasty of stenotic and calcified bioprosthetic valves. Conduit stenosis was severe in all cases, with peak-to-peak systolic pressure gradients of 62 to 100 mm Hg (mean 79 mm Hg) and right ventricular systolic pressures of 87 to 115 mm Hg (mean 100 mm Hg). Three patients had good results, with residual peak-to-peak systolic pressure gradients of 20, 25, and 35 mm Hg. In two other patients, repeated balloon rupture before full inflation occurred, and residual gradients were high (55 and 60 mm Hg). One patient had substantial proximal and distal conduit obstruction in addition to valvular stenosis, and balloon dilation valvuloplasty was not attempted. No complications occurred in five patients; one patient required iliac vein exploration to remove an avulsed balloon fragment. Balloon dilation valvuloplasty can relieve bioprosthetic valve stenosis and postpone conduit replacement in some patients.     

Percutaneous transluminal balloon pulmonary valvoplasty--long-term results

Thirty-two patients with isolated valvar pulmonary stenosis (21 male; 11 female, age range 4 to 53 years, mean 14 years) underwent cardiac catheterization and balloon valvoplasty. Right ventricular systolic pressure before valvoplasty ranged from 65 to 210 mm Hg (mean 120.2 +/- 44.8 mm Hg). It fell to 24-200 mm Hg (mean 73.1 +/- 42.4 mm Hg) immediately after dilation. Peak systolic gradient across the pulmonary valve before valvoplasty ranged from 42 to 193 mm Hg (mean 98 +/- 45.3 mm Hg) and decreased significantly to 5 to 182 mm Hg (mean 52.7 +/- 43.1 mm Hg) immediately after dilation. At repeat cardiac catheterization in 21 patients 3 to 6 months after valvoplasty, a further significant fall of gradient was noted in 15 patients with no change in the remaining six patients. The right ventricular systolic pressure ranged from 30 to 100 mm Hg (mean 55.1 +/- 21.8 mm Hg) while the transpulmonary gradient varied from 12 to 84 mm Hg (mean 34 +/- 23.8 mm Hg). In the four patients evaluated 1 to 1 1/2 years after valvoplasty, the gradient further reduced in 2 patients and was unchanged in the remaining two patients. Patients with isolated valvar pulmonary stenosis can be adequately and safely treated with balloon valvoplasty, without recourse to surgery with excellent immediate and long-term results.     

Long-term results after balloon pulmonary valvuloplasty

BACKGROUND. The objective of this study was to determine the long-term outcome of patients after percutaneous balloon pulmonary valvuloplasty (BPV) treatment of congenital pulmonary valve stenosis. METHODS AND RESULTS. This study represents a case series with duration (mean +/- SD) of follow-up of 4.6 +/- 1.9 years. Forty-six patients with a median age of 4.6 years (range, 3 months to 56 years) had BPV at one academic institution between June 1981 and December 1986. Mean peak systolic pressure gradients from the right ventricle to the pulmonary artery were as follows: before BPV, 70 +/- 36 mm Hg; immediately after BPV, 23 +/- 14 mm Hg; at intermediate follow-up by cardiac catheterization or Doppler echocardiography at less than 2 years after BPV, 23 +/- 16 mm Hg (n = 33); and at long-term follow-up by Doppler at more than 2 years after BPV, 20 +/- 13 mm Hg (n = 42). BPV acutely reduced the gradient to less than 36 mm Hg for 41 of 46 (89%) patients. Available gradients at long-term follow-up were less than 36 mm Hg for 36 of 42 (86%) patients without additional procedures. A patient age of less than 2 years at the initial BPV was a significant risk factor for gradients over 36 mm Hg at follow-up. CONCLUSIONS. BPV provides long-term relief of pulmonary valvular obstruction in the majority of patients. Close follow-up of patients who require BPV at less than 2 years of age is warranted.     

Accuracy of continuous wave Doppler predicted gradient in patients undergoing balloon pulmonary valvoplasty

14 patients who underwent balloon valvoplasty had trans-pulmonic gradient evaluated by continuous wave Doppler echocardiography. Maximum systolic gradients measured from Doppler flow velocities were correlated with peak to peak gradient obtained at cardiac catheterisation. Prior to valvoplasty, there was good correlation between the Doppler maximum gradient (92.85 +/- 34.7mm Hg) and the peak to peak catheter gradient (105.57 +/- 56.60 mm Hg), (r = 0.91, p = less than 0.001). Immediately after balloon valvoplasty, the maximum Doppler gradient did not correlate with the peak to peak catheter gradient (r = 0.33, p = NS). Exclusion of patients with infundibular gradients improved the correlation coefficient between the Doppler maximum and peak to peak catheter gradient to 0.69. At late restudy following valvoplasty, when regression of infundibular stenosis was noted in 6 out of 8 patients, the Doppler maximum and catheter peak to peak gradient had excellent correlation (r = 0.97, p = less than 0.001). In patients with lone valvular gradient immediately following valvoplasty and at late restudy, maximum Doppler gradients correlated well with catheter gradients in 14 estimations (r = 0.66, p = less than 0.01). This study shows that the non-invasive quantification of pulmonary valve stenosis can be reliably undertaken, using continuous wave Doppler echocardiography before balloon valvoplasty and during follow-up, after the procedure when the infundibular stenosis has regressed. The presence of an infundibular gradient immediately after balloon dilatation makes the Doppler prediction less reliable.     

Percutaneous pulmonary valvuloplasty in adults

Percutaneous balloon pulmonary valvuloplasty was performed in 6 adult patients (aged 21-59 years, mean age: 43 years) with congenital pulmonary valve stenosis and systolic pressure gradients of 50 to 120 mm Hg (mean: 78 mm Hg). In 5 patients the procedure was successful: mean systolic right ventricular pressure was reduced from 99 +/- 26 to 55 +/- 7 mm Hg and the trans-stenotic pressure gradient from 77 +/- 28 to 31 +/- 12 mm Hg. Valvuloplasty with a 20 mm balloon was not effective in a patient with a wide pulmonary anulus (diameter 25 mm). In 1 patient only, the balloon occlusion led to severe systemic hypotension with syncope. Short-term follow-up (3 months) demonstrated symptomatic improvement and persistent reduction of the pressure gradient in all successfully treated patients. In conclusion, percutaneous balloon pulmonary valvuloplasty appears to be an effective method with low risk of complications for the treatment of pulmonary valve stenosis in adults.     

Balloon dilation of postoperative right ventricular outflow obstructions

Balloon dilation was attempted in 16 patients, aged 5 months to 19.5 years, with right ventricular outflow obstruction after repair of congenital heart defects. Stenosis of a valved conduit between the pulmonary ventricle and pulmonary artery was present in nine patients with a mean transvalvular peak systolic ejection gradient of 61.6 +/- 21.0 mm Hg and a mean right ventricle to aorta pressure ratio of 0.9 +/- 0.2. Supravalvular pulmonary stenosis was present in seven patients; in five, stenosis was at the anastomotic site after the arterial switch operation with a mean peak systolic ejection gradient of 72.2 +/- 10.6 mm Hg and mean right ventricle to aorta pressure ratio of 0.93 +/- 0.05. The other two patients had stenosis at a previous pulmonary artery band site with a peak systolic ejection gradient of 60 and 65 mm Hg and right ventricle to aorta pressure ratio of 0.75 and 0.72, respectively. Balloon dilation was successful in three of nine patients with a valved conduit; two of them had additional successful balloon dilation of the right pulmonary artery. In five of the nine patients (including one with successful dilation) the conduit was replaced 5.7 +/- 4.5 months after balloon dilation. Balloon dilation was successful in only one of the five patients with supravalvular pulmonary stenosis after the arterial switch operation and partially successful in the two patients with supravalvular pulmonary stenosis at a previous band site. The success rate of balloon dilation of postoperative right ventricular outflow obstruction is much lower than that for other right heart obstructions.     

Balloon dilation of critical pulmonary stenosis in the first week of life

Although balloon dilation or valvular pulmonary stenosis is established in infants and children, the techniques for and results of balloon dilation in neonates with critical pulmonary stenosis remain largely unreported. Since January 1, 1985, six successive neonates with critical pulmonary stenosis (aged 1 to 6 days) underwent attempted balloon dilation. Each was cyanotic and three of the six were on prostaglandin E₁therapy and three required tracheal intubation and ventilation. All had suprasystemic right ventricular pressures (mean 122.8 ± 6.6 mm Hg).After hemodynamic evaluation and right ventricular angiography, the valve was crossed in five patients, and was first dilated with a low profile, 5 or 6 mm diameter, 2 cm long balloon. At least one more balloon was used in each patient, the largest being 95 to 133% of the diameter of the pulmonary valve anulus. The anulus size was 6.8 ± 1.1 mm and the largest balloon size used was 6 to 10 mm.Right ventricular pressure decreased to nearly systemic level or less in live of five patients (58.8 ± 6.7 mm Hg). Pressure gradients, measured in four infants, were 7, 12, 16 and 35 mm Hg, respectively, but were unreliable indicators of obstruction because of a patent ductus arteriosus. The five patients were discharged 3 to 8 (days after balloon dilation. All are currently symptom free 10.6 ± 11.7 months later, and all but one are believed clinically to have mild obstruction. Complications included iliac vein occlusion (n = 1) and complete right bundle branch block (n = 1).Although follow-up has been brief, neonates with critical pulmonary stenosis can safely undergo balloon dilation, usually with good short-term results.     

Important pressure recovery in patients with aortic stenosis and high Doppler gradients.

Pressure recovery has been described in aortic stenosis and may explain the difference occasionally observed between Doppler- and catheter-measured gradients. A narrow ascending aorta (AA) and moderately severe stenosis favors pressure recovery. The aims of this study were to investigate the degree to which these conditions are present in patients with aortic stenosis and high Doppler gradients and to evaluate the magnitude of pressure recovery. One hundred sixteen patients were examined with Doppler echocardiography before aortic valve replacement. Patients with a maximum gradient >70 mm Hg (n = 81) were included. The diameter of the AA was measured and compared with the diameter in an age- and body size-matched group of normal controls (n = 23). Pressure recovery was estimated from a previously validated equation by measuring the maximum Doppler gradient, the effective orifice area (EOA), and the diameter of the AA. The diameter of the AA was similar for patients (mean 3.0 cm, range 2.1 to 4.1) and normal controls (mean 3.0 cm, range 2.3 to 3.5). The maximum Doppler gradient was 107 mm Hg (range 71 to 170) and the EOA was 0.6 cm(2) (range 0.2 to 1.3). The calculated pressure recovery was 18 mm Hg (range 6 to 37), which gives a net gradient of 89 mm Hg (range 51 to 151). Twenty-three percent had a net gradient <70 mm Hg. A cutoff of EOA/AA diameter at >0.2 cm identified 84% of patients (16 of 19) with a net gradient <70 mm Hg. In conclusion, we found that important pressure recovery can be expected in most patients with aortic stenosis and high Doppler gradients. Pressure recovery may explain why some patients with high Doppler gradients are asymptomatic. Also, pressure recovery is a factor to consider in patients with atypical symptomatology and high Doppler gradients when one must decide on valvular replacement.     

Percutaneous pulmonary valvuloplasty

Five patients (aged between 11 and 59 years) with valvular pulmonary artery stenosis and pressure gradients between 60 and 143 mm Hg underwent percutaneous transluminal balloon valvuloplasty. Selection of the appropriate balloon size was based on the measurement of the dimension of the value anulus as a determinant from the angiogram. Balloon catheters were used with a diameter of 18 to 20 mm. After placement in the stenotic valve the balloon was filled with diluted contrast material for 10-20 s. The balloon indention by the stenotic valve disappeared suddenly during expansion with one to three atmospheres. The pressure gradient in individual patients decreased from 60 to 25, from 143 to 60, 100 to 55, 143 to 60, and 60 to 37 mm Hg, in the mean from 101 to 52 mm Hg. All patients were discharged two to four days after the procedure. During follow-up with recatheterization after three to nine months (four patients) the gradients decreased as compared to the value immediately after valvuloplasty. The exercise capacity increased in all patients. No complications were observed. Balloon valvuloplasty of pulmonary valvular stenosis seems to be an alternative to the operative procedure.     

Results of balloon valvuloplasty in the treatment of congenital valvar pulmonary stenosis in children

Transluminal balloon valvuloplasty was used in the treatment of congenital valvar pulmonary stenosis in 19 children, aged 5 months to 18 years. The right ventricular (RV) systolic pressure and RV outflow tract gradient decreased significantly immediately after the procedure (95 +/- 29 vs 59 +/- 14 mm Hg, p less than 0.01, and 78 +/- 27 vs 38 +/- 13 mm Hg, p less than 0.01). Seven of these patients were evaluated at cardiac catheterization 1 year after balloon valvuloplasty. No significant change occurred in RV systolic pressure or RV outflow tract gradient at follow-up evaluation compared with measurements immediately after balloon valvuloplasty (60 +/- 5 mm Hg vs 56 +/- 12 mm Hg and 39 +/- 5 vs 38 +/- 10 mm Hg). In addition, follow-up evaluation was performed using noninvasive methods and included electrocardiography (n = 13), vectorcardiography (n = 11) and Doppler echocardiography (n = 11) Doppler echocardiography in 11 patients 15 +/- 9 months after balloon valvuloplasty showed a continued beneficial effect with a mild further decrease in RV outflow tract gradient. Thus, balloon valvuloplasty is effective in the relief of pulmonary stenosis.     

Results of balloon valvuloplasty in typical and dysplastic pulmonary valve stenosis: Doppler echocardiographic follow-up

To assess the usefulness of balloon valvuloplasty in patients with a dysplastic pulmonary valve, the files of 36 patients (aged 1 day to 18.5 years) who had two-dimensional echocardiography before and continuous wave Doppler echocardiography late after balloon valvuloplasty (balloon diameter greater than or equal to 20% anulus diameter) were reviewed. Results of relief of pulmonary stenosis were graded by catheter gradient in the catheterization laboratory and compared with Doppler echocardiographic findings at follow-up. There were 32 patients with typical pulmonary stenosis and 4 with a dysplastic valve. In the 32 patients with typical pulmonary stenosis, transvalvular gradient changed from a mean of 67 +/- 32 to 20 +/- 20 mm Hg (p less than 0.0001, mean reduction 72.6%). The gradients at follow-up by Doppler echocardiography averaged 20 mm Hg including 15 that increased, 3 that were unchanged and 14 that decreased. Only 3 (9%) of 32 patients had a gradient greater than 25 mm Hg at follow-up and only one gradient was greater than 35 mm Hg. All four patients with a dysplastic valve had a gradient that decreased with valvuloplasty from a mean of 85 +/- 33 to 33 +/- 20 mm Hg (p less than 0.05); gradient reduction in this group ranged from 40 to 85% (mean 57.5%). The gradient at follow-up increased in three of these four patients and decreased in one (the only late gradient less than 25 mm Hg). Late gradient was less than 35 mm Hg in two of the four patients and was reduced by 43 and 57%, respectively, in the other two.(ABSTRACT TRUNCATED AT 250 WORDS)     

Double balloon technique for dilation of valvular or vessel stenosis in congenital and acquired heart disease

Despite the generally excellent success with balloon dilation for the stenotic lesions of congenital and acquired heart disease, technical difficulties sometimes prevent satisfactory results. Such technical difficulties include: a large diameter of the anulus of the stenotic lesion relative to available balloon diameter, difficulty in the insertion or removal of the larger balloon catheters, and permanent damage to or obstruction of the femoral vessels by the redundant deflated balloon material of the large balloons. A double balloon technique was initiated to resolve these difficulties. With this method, percutaneous balloon angioplasty catheters were inserted in right and left femoral vessels, placed side by side across the stenotic lesion and inflated simultaneously. Dilation procedures using the two balloon technique were performed in 41 patients: 18 with pulmonary valve stenosis, 14 with aortic valve stenosis, 5 with mitral valve stenosis, 3 with vena caval obstruction following the Mustard or Senning procedure and 1 with tricuspid valve stenosis. Patient ages ranged from 1 to 75 years (mean 17.8) and patient weights ranged from 8.9 to 89 kg (mean 42.3). Balloon catheter sizes ranged from 10 to 20 mm in diameter. Average maximal pressure gradient in mm Hg before dilation was 61 in pulmonary stenosis, 68 in aortic stenosis, 21 in mitral stenosis, 12 in tricuspid stenosis and 25 in vena caval stenosis. Average maximal valvular pressure gradient after dilation was 13 in pulmonary stenosis, 24 in aortic stenosis, 4 in mitral stenosis, 0 in tricuspid stenosis, and 1 in vena caval stenosis. No major complications were encountered with the procedures.(ABSTRACT TRUNCATED AT 250 WORDS)     

Balloon dilatation for critical pulmonary stenosis.

This study was conducted to investigate the outcome of balloon valvuloplasty for critical pulmonary stenosis in young infants. During a 6.2-year period between January 1992 and February 1998, 34 infants with critical pulmonary stenosis, aged 1 to 58 days (16.8+/-16.6 days), underwent attempted balloon valvuloplasty in this institution. The procedure was accomplished in 28 patients, but failed in six. Surgical pulmonary valvotomy was performed in the six patients with one mortality. Immediately following valvuloplasty, the mean right ventricular systolic pressure decreased from 109.2+/-28.6 to 55.1+/-23.6 mm Hg in the 28 patients (P<0.01). The mean pressure gradient decreased from 85.6+/-29.4 to 26+/-21.4 mm Hg (P<0.01). However, one who had a severely hypoplastic right ventricle requiring prolonged prostaglandin E1 infusion after valvuloplasty underwent a right ventricular outflow tract patch. After a follow-up period ranging from 2 months to 6.4 years (30.5+/-19.1 months), one patient developed recurrent pulmonary stenosis and underwent a repeated balloon valvuloplasty. Of the 27 patients (79%) with a definitive success of balloon valvuloplasty, the mean pressure gradient estimated with Doppler echocardiography at most recent follow-up was 15.2+/-6.8 mm Hg. Therefore, balloon valvuloplasty is the procedure-of-choice for critical pulmonary stenosis. Surgery should be reserved for those with unsuccessful balloon valvuloplasty.     

Percutaneous balloon valvuloplasty for treatment of congenital pulmonary valvular stenosis in children

Percutaneous balloon pulmonary valvuloplasty was performed in seven children with moderate to severe valvular pulmonary stenosis (right ventricular to pulmonary artery pressure gradient greater than 50 mm Hg). All patients experienced a decrease in right ventricular peak systolic pressure from 108 +/- 30 to 60 +/- 5.6 mm Hg (p less than 0.001), decrease in right ventricular to pulmonary artery gradient from 90.1 +/- 30 to 38.8 +/- 5 mm Hg (p less than 0.001) and increase in pulmonary valve area from 0.33 +/- 0.06 to 0.55 +/- 0.15 cm2/m2 (p less than 0.001). In the two patients who underwent supine bicycle exercise before and after valvuloplasty, a significant decrease in both the maximal right ventricular peak systolic pressure (212 to 140 and 175 to 125 mm Hg, respectively) and in right ventricular to pulmonary artery peak pressure gradient (185 to 110 and 151 to 85 mm Hg, respectively) occurred. All patients tolerated the procedure well and no serious complications were observed. It is concluded that percutaneous balloon valvuloplasty is a safe and effective method for relief of right ventricular obstruction due to moderate or severe valvular pulmonary stenosis. However, long-term results remain unknown.     

Estimation of pressure gradients by auscultation: an innovative and accurate physical examination technique

BACKGROUND: Knowledge of pressure gradients across valves, arteries, and ventricular septal defects (VSD) is important in patient management. It was determined how well such gradients can be estimated by auscultation of a murmur's frequencies. METHODS: In 151 patients with pulmonary stenosis (PS) (n = 77), aortic stenosis (AS) (n = 30), or VSD (n = 44), the auscultation gradient was estimated by a murmur's frequencies by use of an "auscultatory scale." The auscultation gradient was recorded before Doppler echocardiography was performed by a blinded cardiac sonographer. RESULTS: Auscultation correlated highly with Doppler echocardiography (Doppler = 0.99. Auscultation + 7.12; r = 0.84, P <.0001). Agreement was good (mean difference [Auscultation - Doppler] = -6.8 +/- 15.8 mm Hg). In 95 patients (63%), agreement was within 10 mm Hg. Auscultation was more accurate when Doppler gradients were < or =60 mm Hg (r = 0.76, P <.0001, vs r = 0.22, P not significant for >60 mm Hg; mean difference -2.6 +/- 10.6 mm Hg vs -16.5 +/- 20.9 mm Hg for >60 mm Hg, P <.0001). Among lesions, PS showed the highest correlation, although agreement for PS, AS, and VSD was not significantly different. Isolated valvar PS showed excellent accuracy (r = 0.92, P <.0001; mean difference -5.6 +/- 8.9 mm Hg). CONCLUSIONS: Auscultation of a murmur's frequency composition can estimate gradients accurately in most patients with PS (especially valvar PS), AS, or VSD, although it is less accurate for gradients >60 mm Hg. This innovative technique can improve diagnostic accuracy, thereby further substantiating the value of physical examination.     

"Overestimation" of catheter gradients by Doppler ultrasound in patients with aortic stenosis: a predictable manifestation of pressure recovery.

OBJECTIVES: This study sought to evaluate whether pressure recovery can cause significant differences between Doppler and catheter gradients in patients with aortic stenosis, and whether these differences can be predicted by Doppler echocardiography. BACKGROUND: Pressure recovery has been shown to be a source of discrepancy between Doppler and catheter gradients across aortic stenoses in vitro. However, the clinical relevance of this phenomenon for the Doppler assessment of aortic stenosis has not been evaluated in patients. METHODS: Twenty-three patients with various degrees of aortic stenosis were studied with Doppler echocardiography and catheter technique within 24 h. Using an equation previously validated in vitro, pressure recovery was estimated from peak transvalvular velocity, aortic valve area and cross-sectional area of the ascending aorta and compared with the observed differences between Doppler and catheter gradients. Doppler gradients were also corrected by subtracting the predicted pressure recovery and then were compared with the observed catheter gradients. RESULTS: Predicted differences between Doppler and catheter gradients due to pressure recovery ranged from 5 to 82 mm Hg (mean +/- SD, 19 +/- 16 mm Hg) and 3 to 54 mm Hg (12 +/- 11 mm Hg) for peak and mean gradients, respectively. They compared well with the observed Doppler-catheter gradient differences, ranging from -5 to 75 mm Hg (18 +/- 18 mm Hg) and -7 to 48 mm Hg (11 +/- 13 mm Hg). Good correlation between predicted pressure recovery and observed gradient differences was found (r = 0.90 and 0.85, respectively). Both the noncorrected and the corrected Doppler gradients correlated well with the catheter gradients (r = 0.93-0.97). However, noncorrected Doppler gradients significantly overestimated the catheter gradients (slopes, 1.36 and 1.25 for peak and mean gradients, respectively), while Doppler gradients corrected for pressure recovery showed good agreement with catheter gradients (slopes, 1.03 and 0.96; standard error of estimate [SEE] 8.1 and 6.9 mm Hg; mean difference +/- SD 0.4 +/- 8.0 mm Hg and 1.1 +/- 6.8 mm Hg for peak and mean gradients, respectively). CONCLUSIONS: Significant pressure recovery can occur in patients with aortic stenosis and can cause discrepancies between Doppler and catheter gradients. However, pressure recovery and the resulting differences between Doppler and catheter measurements may be predicted from Doppler velocity, aortic valve area and size of the ascending aorta.     

Immediate and follow-up results of transluminal balloon dilation for discrete subaortic stenosis.

This study presents the findings in 33 patients with discrete subaortic stenosis who were treated by percutaneous balloon dilation and were followed up for 2 months to 6.2 years (mean 34 +/- 21 months). The mean age was 13 +/- 11 years; 10 (30%) were female and 23 (70%) male. Associated malformations were observed in nine patients (27%). All patients underwent noninvasive studies and cardiac catheterization. The mean value to membrane distance was 4.5 +/- 2 mm/m2. After balloon dilation, the pressure gradient from the left ventricle to the aorta decreased from 68 +/- 30 to 20 +/- 13 mm Hg (p less than 0.00001); there were no significant changes in the degree of aortic regurgitation. A fluttering and widely mobile remaining membrane was clearly visualized after dilation. Better immediate results were obtained in patients with a smaller baseline gradient, a larger aortic anulus and a longer valve to membrane distance. Serial follow-up echographic studies were available in 30 patients, and 18 hemodynamic reevaluations were performed in 13 patients. However, seven patients who demonstrated restenosis underwent redilation at a mean of 29 +/- 17 months after the first dilation. Redilation in six of the seven patients obtained benefits similar to those observed at the first dilation. Only one patient with unsuccessful redilation required surgery. The mean value of the last explored residual gradient (on hemodynamic or Doppler study) in the remaining 32 patients was 21 +/- 10 mm Hg. No significant changes were observed in the angiographic evolution of aortic regurgitation.(ABSTRACT TRUNCATED AT 250 WORDS)     

Percutaneous mitral valvuloplasty in an adult patient with calcific rheumatic mitral stenosis

A 75 year old man with long-standing rheumatic mitral stenosis who refused surgical intervention was treated with percutaneous balloon valvuloplasty. Prevalvuloplasty evaluation revealed a heavily calcified mitral valve, a mean transvalvular gradient of 18 mm Hg, a Fick cardiac index of 1.7 liters/min per m2, a mitral valve area of 0.6 cm2 and 1 + mitral regurgitation. After transeptal catheterization and balloon dilation of the interatrial septum with an 8 mm angioplasty balloon, a 25 mm valvuloplasty balloon was advanced over a guide wire across the interatrial septum and positioned across the mitral anulus. Subsequent balloon inflation at 3 atm pressure resulted in a reduction of the mean mitral valve gradient to 12 mm Hg, an increase in cardiac index to 2.5 liters/min per m2, an increase in mitral valve area in 1.4 cm2 and an increase in mitral regurgitation from 1 + to 2 +. Valvuloplasty was well tolerated without embolization of clot or valvular debris, and resulted in marked clinical improvement with decreased dyspnea and increased exercise tolerance. Repeat catheterization 2 months after valvuloplasty showed further resolution of pulmonary hypertension and no evidence of valvular restenosis or worsening mitral regurgitation, but detected a small atrial septal defect with a pulmonary to systemic blood flow ratio of 1.8. It is concluded that percutaneous valvuloplasty is possible in the adult patient with calcific rheumatic mitral stenosis, and may result in a significant improvement in valvular function without producing life-threatening complications.     

Use of Balloon-Expandable Stents for Coarctation of the Aorta: Initial Results and Intermediate-Term Follow-Up

Objectives. In this study we report our preliminary results and intermediate-term follow-up (up to 3.5 years) of stent implantation for coarctation of the aorta (COA).

Background. Balloon angioplasty has gained acceptance as a modality of treatment for COA. Some patients do not respond optimally to balloon angioplasty alone. Balloon-expandable stents have been used in pulmonary arteries and large systemic arteries such as the femoroiliac vessels, with a significant improvement in vessel patency and a reduction in the pressure gradient compared with balloon angioplasty alone.

Methods. Nine patients (>10 years old) with COA in whom balloon dilation alone was thought to be ineffective underwent stent implantation. Seven patients had a previous operation or balloon dilation, or both, to relieve their coarctation but had a significant residual/recurrent gradient.

Results. At the time of stent implantation, the systolic and mean gradients decreased from a mean (±SEM) of 37 ± 7 and 14 ± 3 mm Hg to 4 ± 1 and 2 ± 0.6 mm Hg, respectively (p ≤ 0.002). The coarctation diameter increased from a mean of 9 ± 1 to 15 ± 1 mm (p < 0.002). The patients have been followed for up to 42 months (mean 18, median 13) with no complications; the stents remain in position with no fracture. One patient underwent further successful dilation 3 years after stent implantation because of an exercise-induced gradient. No other intervention has been required. The systolic gradient at latest follow-up is 7 ± 2 mm Hg. Only two (a 44-year old with diabetes and a 50-year old with long-standing hypertension) of five patients previously requiring antihypertensive treatment still remain on medications for blood pressure control.

Conclusions. The use of stents in COA is a feasible alternative to surgical repair or balloon angioplasty in selected patients with an effective gradient reduction. Intermediate-term follow-up shows excellent gradient relief, with no complications in this group of patients.