Differential regulation of atrial and brain natriuretic peptides and its implications for the management of left ventricular volume overload

BACKGROUND

In this study, we investigated the possibility that the atrial and brain natriuretic peptide expression in left ventricular volume overload (VOL) is transcriptionally regulated. We further evaluated the diagnostic and/or prognostic potential of this expression for the management of patients with this disorder.

DESIGN

We compared the myocardial mRNA expression and plasma levels of the two peptides in VOL patients using donor hearts and in healthy blood donors as controls.

RESULTS

The atrial natriuretic peptide (ANP) mRNA was elevated by 38% (P < 0.03) in the right atrium and by 53% (P < 0.003) in the left atrium, but was unchanged in the ventricular chambers of the patient group (n = 19) compared with controls (n = 8). Plasma ANP concentration was elevated by 62% (P < 0.001) compared with blood donor controls (n = 79). It increased slightly (by 36%) 2 h following surgery, and remained at 64% higher (P < 0.03 vs. presurgery) for the 5 days following surgery. The brain natriuretic peptide (BNP) mRNA was elevated by approximately one-fold in both the left ventricle (P < 0.02) and right atrium (P < 0.05), by 94% (P < 0.02) in the right ventricle and by 89% (P < 0.05) in the left atrium. Its plasma level in the patients was 3.4-fold (P < 0.00003) higher than in control subjects. It increased significantly by 1.2-fold (P < 0.01) 2 h following surgery, but dropped significantly (P < 0.05 vs. 2 h post surgery) to presurgical levels 5 days following surgery.

CONCLUSION

The results show chamber-specific elevation in both atrial and brain natriuretic peptide expression and differences in their circulating levels in VOL, suggesting that BNP is a potential prognostic indicator in the postsurgical management of these patients.

Evaluation of a new device for quick sutureless coronary artery anastomosis in surviving sheep

OBJECTIVE

A new device for performing quick sutureless vascular anastomosis by means of stent technology has recently been developed by Jomed International, Helsingborg, Sweden. The efficacy of this GraftConnector was studied in a sheep model.

METHODS

In adult sheep, a left anterior thoracotomy under the fourth rib extended across the sternum gave good access to the left anterior descending branch (LAD) and the right internal mammary artery (RIMA). On beating hearts, the GraftConnector group had the RIMA connected to the LAD by means of the new device, while the control animals had the same anastomoses sutured with continuous 7-0 polypropylene sutures. The time for completing the anastomosis (ischemic time) was recorded and the blood flow in the RIMA was recorded with the proximal LAD open and closed, respectively. An intra-operative fluoroscopy with contrast injection directly into the graft was done. Finally the proximal LAD was ligated. The surviving animals are to be followed up.

RESULTS

Seven (46%) of the 15 animals operated on with the traditional suturing technique and seven (63%) of the 11 GraftConnector sheep survived the procedures and are to be followed up. The 11 anastomoses done with the GraftConnector were completed in 2.41+/-0.2 min, and the 14 anastomoses sutured with continuous suture were completed in 6.93+/-0.419 min (P<0.0001). The RIMA blood-flows in the two groups were comparable and are presented. All the surviving animals had open anastomoses at fluoroscopy.

CONCLUSIONS

Quick coronary artery anastomoses without suturing on beating hearts can be completed with the new GraftConnector. The GraftConnector creates reproducible anastomoses in much less time than suturing, the per-operative mortality in the GraftConnector Group was accordingly lower. Long-time follow-up of the patency in surviving animals is pending. The presented device may ultimately permit quick anastomoses endoscopically.

Double-chambered right ventricle in 73 patients: spectrum of the disease and surgical results of transatrial repair

OBJECTIVE

To review the spectrum of double-chambered right ventricle (DCRV) and the outcome of surgical repair in patients diagnosed between February 1988 and March 1999.

DESIGN

The charts of patients with DCRV were studied.

SETTING

Tertiary care hospital.

PATIENTS AND METHODS

A total of 73 patients were identified. Sixty-nine underwent surgical repair, while four are awaiting surgery. The repair was through a transatrial approach in 61 patients, while in eight an additional ventriculotomy was performed.

MAIN RESULTS

An associated ventricular septal defect (VSD) was present in 56 of 73 patients (77%). These patients were significantly younger (P<0.05) than the 17 patients without a VSD. Among patients with a VSD, the 31 requiring patch closure were significantly younger than the 25 patients having direct closure. Five older patients among those with intact septum had impaired right ventricular (RV) function as well as higher intraventricular gradients. At surgery the intraventricular obstruction was relieved by myomectomy. There was no hospital or late mortality. Following surgery, at a mean follow-up of 13.6 months, no increase in the intraventricular gradient was detected by Doppler echocardiography.

CONCLUSIONS

The development of DCRV is associated with VSD in early life. The probability of the presence of a VSD decreases with age. The disease is progressive, resulting in increased intracavitary gradient within the RV and in RV impairment if it is not treated in a timely fashion. Transatrial repair is safe with excellent midterm results. In the presence of high gradients within the RV, a ventriculotomy may be necessary to obtain acceptable results.

Results of the Ross operation in rheumatic versus non-rheumatic aortic valve disease

BACKGROUND AND AIM OF THE STUDY

A total of 213 patients underwent the Ross operation at our institution between January 1990 and January 1999. Outcome was assessed in rheumatic (RH) patients and compared with that in patients with other etiology (non-RH).

METHODS

After exclusion of 69 patients with a follow up of <18 months, the study group comprised 144 patients (119 RH, 25 non-RH). Patients were studied clinically and by echo-Doppler cardiography preoperatively, within 2 months and 6-8 months after surgery, and yearly afterwards. Preoperative assessment included age, gender, body surface area (BSA), type of aortic valve lesion and additional valve disease, left and right ventricular outflow tract (LVOT, RVOT) dimensions, and left ventricular (LV) size, function and mass. Postoperatively, patients were studied for presence and severity of autograft regurgitation, mitral regurgitation, LV size, function and mass, and incidence and timing of reoperation.

RESULTS

On average, RH patients were older and had higher BSA, more aortic regurgitation than stenosis, more additional mitral valve disease (mostly regurgitation), larger LV size and poorer LV function. Mitral valve repair was performed in 24% of RH patients versus 0% of non-RH patients. Postoperatively, differences in LV size, function and mass remained present, but diminished during follow up. The autograft reoperation incidence was 22% (26/119) in RH patients versus 8% (2/25) in non-RH patients (p = NS). Preoperative predictors for reoperation in the RH group were severe concomitant mitral regurgitation (MR), followed by male gender and large indexed LVOT (all p<0.001 by discriminant analysis).

CONCLUSION

Marked differences were present in patient characteristics between rheumatic and nonrheumatic patients who underwent the Ross operation. Rheumatic patients had a higher incidence of autograft reoperation. Severe concomitant MR was the most important predictor for reoperation in rheumatic patients.

Aneurysms complicating pulmonary autograft procedure for aortic valve replacement

Aneurysm formation in the left ventricular outflow tract related to the proximal end of the pulmonary autograft after the Ross procedure was present in 2 patients. Both occurred late after operation and were associated with prolapse of a leaflet of the autograft and significant regurgitation. Both were repaired with no immediate complications. There was no evidence of infection at time of operation. The probable mechanisms underlying this complication and the possibilities of avoiding it are discussed.

The long-term effect of successful mitral balloon valvotomy on left atrial size

BACKGROUND AND AIM OF THE STUDY

The study aim was to determine the extent of regression of left atrial (LA) enlargement following mitral balloon valvotomy (MBV) for mitral stenosis.

METHODS

Data obtained from 205 patients before, and at a mean of 31.0 +/- 21.1 months (range: 6 to 86.3 months) after successful MBV were analyzed retrospectively.

RESULTS

The invasively determined mitral valve area increased from 0.81 +/- 0.27 cm2 at baseline to 1.73 +/- 0.54 cm2 immediately after valvotomy (p <0.0001), and the mean mitral gradient fell from 15.6 +/- 5.3 to 5.4 +/- 2.5 mmHg (p <0.0001). Similar changes were noted in Doppler-determined mitral valve area (0.89 +/- 0.16 to 1.97 +/- 0.29 cm2; p <0.0001) and gradient (12.6 +/- 5.3 to 4.9 +/- 1.7 mmHg; p <0.0001). In comparison with baseline, significant (p <0.0001) reductions were noted at follow up in the echocardiographic anteroposterior (48.7 +/- 6.9 to 42.4 +/- 6.6 mm), superior-inferior (68.5 +/-8.1 to 59.6 +/- 8.2 mm) and medial-lateral LA dimension (51.2 +/- 6.7 to 44.1 +/- 7.7 mm) and calculated LA volume (91.6 +/- 29.1 to 60.7 +/- 23.8 cm3) Patients in atrial fibrillation had larger LA dimensions, but substantially smaller absolute and relative reduction in LA size at follow up than patients in sinus rhythm. Among patients with prevalvotomy LA enlargement, normalization of LA dimension at follow up was seen in 29.2% of patients in sinus rhythm, but in none of the 32 with atrial fibrillation.

CONCLUSIONS

Successful MBV results in significant long-term reduction in LA size in most patients, but normalization of LA size is unusual.

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.

Treated bovine and autologous pericardium for aortic valve reconstruction

BACKGROUND

To determine the differences in clinical behavior of bovine versus autologous pericardium, all consecutive patients undergoing aortic valve reconstruction were reviewed.

METHODS

Between October 1988 and December 1995, 91 patients (mean age 30 years) underwent reconstruction with bovine (n = 27) or autologous (n = 64) pericardium.

RESULTS

There were 2 hospital deaths, 5 late deaths, and no embolic events. Dysfunction of the aortic reconstruction required reoperation in 6 bovine (infection 1, fibrocalcific 5) and in 5 autologous (infection 3, annulus dilatation 1, commissural tear 1). Actuarial survival and freedom from structural deterioration at 8 years were 82.2%+/-9.6% and 76.2%+/-10.7% for bovine and 91.05%+/-3.96% and 96.8%+/-2.25% for autologous pericardium, respectively. The last Doppler echocardiographic study showed a mean regurgitation (1 to 4+) and gradient in the bovine pericardium of 1.25+/-and 20.7 mm Hg and in the autologous pericardium of 1+ and 7.7 mm Hg.

CONCLUSIONS

Aortic valve reconstruction with pericardium can be safely performed with low thromboembolic rate. At 8 years follow up, there is a difference in favor of the autologous pericardium.

Reconstruction of supravalvar aortic stenosis with autologous pulmonary artery

Use of autologous tissue in corrective cardiac operations offers many advantages including the potential for growth. We report a surgical technique using autologous pulmonary artery in the repair of supravalvar aortic stenosis in a 6-year-old child. At 30 months' follow-up, the pulmonary arterial tissue shows no evidence of calcification or dilatation and appears to be growing with the aorta.

Clinical results and radiographic appearance of the Rashkind double umbrella device in patients with occlusion of the ductus arteriosus

BACKGROUND

The Rashkind double umbrella device for patent arterial duct occlusion has been used in many patients. Its radiographic appearance has not been sufficiently described.

OBJECTIVE

To present the varying radiographic appearances of the Rashkind double umbrella device on the chest X-ray.

MATERIALS AND METHODS

The chest radiographs of 69 patients (median age 60 months; median weight 17 kg), who underwent closure of their patent arterial duct between March 1990 and August 1994, were reviewed. The following parameters were evaluated: 1) the size of the heart (cardio-thoracic ratio) and pulmonary vessels, 2) the position of the device in AP/PA and lateral projections. The results of occlusion of the patent arterial duct were also reviewed.

RESULTS

Sixty-two of 69 (90 %) patients had complete occlusion after a follow-up between 2 months and 3(1)/2 years. The cardio-thoracic ratio showed significant reduction at follow-up (P < 0.001). The two different size devices could be well differentiated in the AP and the lateral projection. In 14 patients (20 %) the device was in an asymmetrical position. There was no significant correlation between position of the device and success of occlusion in our material.

CONCLUSION

Complete occlusion of the arterial duct using Rashkind double umbrella devices can be achieved in 90 % of our population. In 20 % the device will have an asymmetrical position. There is no correlation between asymmetrical position of the device in the chest radiograph and residual shunting.

Extracardiac right atrium-to-right ventricle homograft for uncorrectable tricuspid valve disease

Surgically uncorrectable tricuspid valve disease in children is rare. However, when it happens the surgical options are very limited. Tricuspid valve replacement using a mechanical valve or stented bioprosthesis is impractical. Use of homografts in the "anatomic position" has its limitations. We report here the use of an extracardiac homograft connection between the right atrium and right ventricle in a 16-month-old boy in whom severe tricuspid valve stenosis developed after surgical repair of a complex ventricular septal defect associated with dextrocardia and anomalous systemic venous drainage. The patient remains well receiving no cardiac medication 12 months after the procedure.

Rheumatic involvement of all four heart valves--preoperative echocardiographic diagnosis and successful surgical management

Rheumatic disease of all four heart valves is rare. We report on a patient with quadrivalvar involvement by rheumatic disease, diagnosed preoperatively by echocardiography, who underwent successful surgical correction. The implications of organic involvement of the pulmonary valve by rheumatic process is discussed.

Heart valve surgery in a young predominantly rheumatic population

Between August 1988G and August 1992G, 802 Saudi patients underwent 1,171 open valve surgical procedures at King Faisal Specialist Hospital and Research Centre (KFSH&RC). The mean age was 32.4 years (range one to 90). The etiology was rheumatic in 66.3%, congenital in 12.8%, degenerative in 8.7%, infective in 5.9% and ischemic in 2%. The mean preoperative New York Heart Association (NYHA) functional class was 2.94 and 74% of the patients were in sinus rhythm. Multiple valve procedures were required in 39.4% of the cases and 718 valves (64.6%) were repaired. The overall hospital mortality was 4.48%. The mortality for isolated mitral valve repair was 1.8% against 3.48% for replacement. For isolated aortic repair, it was 0 against 8.5% for replacement. The follow-up of our patients was 98.1%. During the follow-up period of 1,171.06 patient years, the total incidence of thromboembolic events was 2.35% or 1.53% pt-yrs. Reoperation was required in 7.3% of the patients. The main cause was dysfunction of the rheumatic mitral repairs in the young patients. The late mortality was 3.78%. The actuarial survival for the total 802 operated patients was 86.27%. This survival was 91.10% for those undergoing repair versus 82.10% for those with replacement (P<0.005). It is concluded that a careful and complete follow-up of our patients is essential to determine the value of the available surgical techniques. The young rheumatic patient, so prevalent in our population, remains a surgical challenge. New surgical alternatives are needed.

Endomyocardial fibrosis: Clinical, echocardiographic and hemodynamic findings

Endomyocardial fibrosis (EMF) is a disease of unknown origin. It was first described by Davies in Uganda in 1948. The clinical enchocardiographic, and hemodynamic findings in 18 patients are presented. Six patients had right-sided involvement, four had left-sided involvement and eight had biventricular involvement. The presence of a small ventricle with obliteration of the apex and a large atrium, diagnosed by two-dimensional echocardiography, is highly suggestive of endomyocardial fibrosis. Ventricular angiography was diagnostic in 17 out of 18 cases. Endomyocardial biopsy yielded positive findings in three out of seven patients and is not essential for diagnosis. Two patients suffered a cerebral embolism. Six patients underwent surgery with good results in three patients.