Mitral valve replacement in the presence of severe pulmonary hypertension.

Thirty patients with severe preoperative pulmonary hypertension (pulmonary artery pressure range 90-165 mmHg, mean 118 mmHg) were reviewed following single mitral valve replacement, with prosthetic valves, within the last 10 years (1964-74). The early and late mortality for this group was no different from that of the total series of mitral valve replacements performed over the same period. Marked postoperative clinical improvement was accompanied by corresponding radiological and electrocardiographic changes. In addition there was a statistically highly significant haemodynamic improvement in the 21 survivors (mean survival time 5 1/2 years). At recatheterization the mean pulmonary artery pressure was 41-5%, the mean wedge pressure 46-3%, and the transpulmonary gradient (PAm-LAm) 36-1% of the preoperative values. It is concluded that gross pulmonary hypertension is not per se a contraindication to mitral valve replacement surgery.     

Clinical experience with Sorin Bicarbon valve in patients with tight mitral valve stenosis and elevated pulmonary hypertension (early and mid-term results)

BACKGROUND: The results of mitral valve replacement (MVR) with Sorin mechanical valves in patients who had tight mitral stenosis with high pulmonary artery pressure were reviewed. METHODS: During a period of two years, from August 1998 to May 2000, a mitral valve replacement with a Sorin Bicarbon mechanical valve was performed in 51 patients with a diagnosis of tight mitral stenosis associated with severe pulmonary hypertension (preoperative mean systolic pulmonary artery pressure was 72+/-12 mmHg, range from 60 to 105 mmHg). There were 37 women and 14 men; mean age was 47.2+/-12 years. Forty-eight patients (94.12%) were in NYHA functional class III or IV. All the patients discharged from the hospital were submitted to a clinical follow-up program. A 100% follow-up was obtained with a mean of 12.6+/-6.4 months (range 2 to25 months). RESULTS: Operative mortality was 3.9%, 2 patients who had concomitant CABG died due to low cardiac output. Twelve patients (23.5%) needed an inotropic pharmacological support during the postoperative time. In one patient a re-exploration for bleeding was necessary, and in another one a cerebrovascular accident occurred 3 days after the operation. After 6 months, one patient was reoperated on because of mechanical valve dysfunction due to pannus formation. All survivors underwent a postoperative echocardiographic assessment. The systolic PAP decreased from a mean preoperative value of 72+/-12 mmHg to 39.9+/-12 mmHg. NYHA functional status significantly improved and 86% of the patients were in NYHA functional class I or II. CONCLUSIONS: The mitral valve replacement with Bicarbon mechanical valve prosthesis shows excellent results in patients with mitral valve stenosis associated with a severe pulmonary hypertension.     

Acute Hemodynamic Alterations after Mitral Valve Replacement with the Glutaraldehyde-Treated Porcine Heterograft Prosthesis

Perioperative hemodynamic changes following mitral valve replacement using the porcine heterograft prosthesis were measured in 21 patients with acquired mitral valve disease. Preoperatively, a state of compensatory cardiac failure was suggested by the following: an increased heart rate (HR) (96 beats per minute); low cardiac and stroke volume (SVI) indices (2.3 ± 0.10 L/min/m² and 25 ± 2 ml/beat/m²); and increased systemic vascular resistance (SVR) (1,626 ± 116 dyne sec cm^?5). Both the mean pulmonary artery (PAP) and pulmonary capillary wedge pressures (PCWP) were elevated as well (32 ± 3 and 22 ± 2 torr). Immediate hemodynamic improvement followed valve replacement. HR, SVR, PAP, and PCWP all decreased significantly. Twenty-four hours after valve replacement, PAP (23 ± 1 torr) and PCWP (13 ± 1 torr) demonstrated marked declines, SVR was reduced by one-third (1,173 ± 87 dyne sec cm^?5), HR had decreased by 10 beats per minute, and SVI had increased to 30 ± 2 ml/beat/m². The prompt circulatory improvement of patients soon after mitral valve replacement using the porcine heterograft compares favorably with studies in which other valve types were employed and in which postoperative cardiovascular depression was encountered frequently.     

Inhaled nitric oxide after mitral valve replacement in patients with chronic pulmonary artery hypertension.

Patients with mitral valve disease can develop pulmonary artery hypertension that persists after mitral valve replacement. In 1987, nitric oxide (NO) was reported to be an important factor accounting for the biologic activity of endothelium-derived relaxing factor. Inhaled NO was subsequently reported to be a selective pulmonary vasodilator in animals and patients. Therefore we investigated the vasodilating effect of inhaled NO in patients with mild pulmonary artery hypertension after mitral valve replacement. Six patients who underwent mitral valve replacement for mitral stenosis presented with a mean pulmonary artery pressure greater than 25 mmHg within 24 h after surgery. During mechanical ventilation at FIO2 0.5, NO (36.8-38.4 ppm) was breathed for 10 min. Hemodynamic data were recorded before NO, after 10 min of NO inhalation, and 30 min after the end of NO inhalation. Statistically significant (P < 0.05) hemodynamic response to inhaled NO included a transient decrease in systolic (-10%), diastolic (-8%), and mean (-10%) pulmonary artery pressures; a decrease in pulmonary vascular resistance (-22%); an increase in mixed venous hemoglobin O2 saturation (+6%); and a decrease in arteriovenous O2 content difference (-7%). During NO inhalation, there was no change in systemic arterial or pulmonary wedge pressures. Methemoglobin levels remained < 1%. Inhalation of this concentration of NO for 10 min causes transient pulmonary artery vasodilation and hemodynamic improvement in patients with mild chronic pulmonary artery hypertension after mitral valve replacement.     

A case of pulmonary arteriovenous fistula with mitral stenosis

The patient was a 61-year-old female, complaining of cyanosis, dyspnea and shortness of breath on exertion. She was diagnosed as having a pulmonary arteriovenous fistula (PAVF) in combination with mitral stenosis. The fistula was located in the left lower lobe and a right-left shunt of 28.7% was detected. Cardiac catheterization showed a pulmonary artery pressure of 44/22 mmHg (mean pressure, 31 mmHg). By occluding the PAVF using a balloon catheter, PaO2 increased from 47 mmHg to 88 mmHg. The mitral stenosis of this patient was though to be a mild form, and PAVF seemed to be responsible for symptoms. Since left lobectomy together with mitral valve replacement was considered to have a high risk, left lower lobectomy was performed initially. Thereafter mitral valve replacement was done successfully. Separate operations for PAVF and mitral stenosis are likely to be beneficial in patients with mitral stenosis associated with moderate pulmonary hypertension.     

Experience with Repair of Complete Atrioventricular Canal

Twenty-nine patients at our institution have undergone repair of complete atrioventricular canal since 1969. There were 3 operative and 5 late deaths, 4 of which were of infectious etiology. Age at operation ranged from 2 months to 12 years (mean, 50 months). Weight ranged from 3.6 kg to 30 kg (mean, 12 kg). Before repair, catheterization studies revealed pulmonary hypertension in all patients with unobstructed pulmonary arteries. Pulmonary to systemic flow ratio ranged from 1.5 to 10.6 (mean, 3.5). Pulmonary vascular resistance (PVR) ranged from 0.7 to 21.7 (mean, 5.3) Wood units/m². At repair, 14 patients had Rastelli type A anatomy, 14 had type C, and 1 patient had a variant with crossing chordae and double-outlet right ventricle (DORV).Postoperative catheterization has been done in 16 patients 2 months to 8 years (mean, 30 months) after repair. One patient had residual ventricular shunting and later underwent successful repair. A 2-year-old patient had severe mitral regurgitation and died following mitral valve replacement. One patient required a permanent pacemaker. The 21 surviving patients have been followed from 7 months to 10 years 7 months and have excellent hemodynamic status. Long-term studies are needed to assess the ultimate effect on patients with high PVR.     

Mitral valve replacement using bileaflet mechanical prosthetic valve in the first year of life.

OBJECTIVE: The operative management and long term outcome of mitral valve replacement in infancy remain a therapeutic challenge. The selection of a prosthetic valve for this particular age group might affect the clinical outcome. Here we present our experience of mitral valve replacement in 6 infants using small bileaflet mechanical prosthetic valves. METHODS: Between January 1994 and August 1997, 6 infants (their age ranged from 3 months to 11 months, and their body weight from 2978 g to 7403 g) underwent mitral valve replacement using a mechanical valve prosthesis (16 mm CarboMedics prosthetic valve in 5, and 17 mm St. Jude Medical prosthetic valve Hemodynamic Plus in 1). The preoperative morphological features of the mitral valve were stenosis in 1, regurgitation in 3, and a combination of these in 2. The prosthesis was fixed at the annulus in 3, and at the supra-annular position in 3. Anticoagulation was performed using warfarin. RESULTS: There was no operative mortality. Postoperative catheterization revealed an acceptable wedge pressure in the pulmonary arteries, ranging from 10 to 12 mmHg. During the mean follow-up period of 36 months, late death due to residual pulmonary hypertension occurred in 1 patient at 10 months after surgery. Excluding this patient, all remaining patients are doing well with no need for repeated operation with no thromboembolic complication. The actuarial survival rate and the reoperation free rate at 70 months are 83 +/- 15% and 100%, respectively. CONCLUSION: Mitral valve replacement using a small size bileaflet mechanical prosthetic valves in infancy can be performed with low operative mortality and with satisfactory mid-term results.     

心脏移植患者术前肺动脉压力与术后并发症的关系及防治

目的分析心脏移植患者术前肺动脉压力和肺血管阻力（PVR）与术后右心功能不全、并发症发生和死亡的关系,总结围术期肺动脉高压的管理经验,以利于心脏移植术后患者早期心功能的恢复。方法125例接受同种原位心脏移植手术的患者,根据术前肺动脉收缩压（PASP）和PVR不同分为两组,肺动脉高压组（n=56）：术前PASP〉50 mm Hg或PVR〉5 Wood.U;对照组（n=69）：术前PASP≤50 mm Hg,PVR≤5 Wood.U。通过Swan-Ganz导管监测两组手术前心脏排血指数（CI）,手术前、后肺动脉     

Complete rupture of the posterior papillary muscle caused by late reperfusion for acute myocardial infarction

We describe a patient with acute mitral regurgitation due to complete rupture of the papillary muscle immediately after successful late reperfusion for inferior myocardial infarction. An 81-year-old woman was admitted complaining of mild chest discomfort. Although the electrocardiograms, biochemical test results, and her clinical history showed that several days had passed since the onset of acute myocardial infarction, a late coronary stenting was performed. Immediately after successful stenting, she suddenly developed acute pulmonary edema, leading to cardiogenic shock. In addition to high pulmonary capillary wedge pressure (mean 35 mmHg), color Doppler imaging revealed massive mitral regurgitation caused by complete rupture of the posterior papillary muscle. Emergent mitral valve replacement with a prosthetic valve was performed, saving the patient. Hence, late reperfusion should be considered carefully when treating a patient with a high risk, such as an elderly patient or a patient with single-vessel disease or initial transmural myocardial infarction.     

Inhaled prostacyclin, nitric oxide, and nitroprusside in pulmonary hypertension after mitral valve replacement

OBJECTIVE: Pulmonary hypertension increases morbidity and mortality in patients undergoing heart surgery. Mitral valve stenosis is frequently associated with an increase in pulmonary vascular resistance (PVR). Cardiopulmonary bypass exacerbates pulmonary hypertension in patients undergoing cardiac surgery. The aim of this study was to compare the hemodynamic effects of inhaled prostacyclin and nitric oxide and the administration of i.v. nitroprusside during cardiac surgery with a clinical, pharmacodynamic dose-response, prospective, randomized, and double-blind study (Group A: inhaled prostacyclin; Group B: inhaled nitric oxide; Group C: nitroprusside). MATERIALS AND METHODS: Fifty-eight patients with mitral valve stenosis and elevated PVR (>200 dynes sec/cm5) after mitral valve surgery were studied. Inhaled prostacyclin and nitric oxide were administered at concentrations of 10 g/min and 20 ppm, respectively. Nitroprusside i.v. was administered at the dose of 5-15 g/min. RESULTS: Prostacyclin and nitric oxide produced a significant dose-related decrease of mean pulmonary arterial pressure, pulmonary vascular resistance, and transpulmonary gradient. A significant increase in cardiac output was observed in both groups. In Group C, nitroprusside administration was interrupted in 62% patients due to occurrence of systemic hypotension. CONCLUSIONS: Inhaled prostacyclin and nitric oxide are effective in the treatment of postoperative pulmonary hypertension in patients with mitral valve stenosis undergoing mitral valve surgery. Both drugs improve cardiac output and reduce mean pulmonary arterial pressure, pulmonary vascular resistance, and trans-pulmonary gradient. They may be useful in patients with acute right ventricular failure following cardiac surgery. In comparison to nitric oxide, inhaled prostacyclin is free from toxic side effects and is easier to administer.     

Repair of ventricular septal defect in adults

To evaluate the outcome of ventricular septal defect (VSD) with long duration of haemodynamic derangement, a retrospective study was made of 42 consecutive patients who underwent closure of VSD as adults (age range 15-48, mean 27 years). The mean systolic pulmonary arterial pressure was 53 mmHg, mean pulmonary vascular resistance 2.5 Wood units and mean pulmonary/systemic flow ratio 2.4. VSD was complicated by aortic regurgitation in 12 cases, mitral regurgitation in 4, and sinus of Valsalva fistula in 6 cases. There were 15 supracristal, 24 infracristal and 3 muscular VSDs. In addition to VSD closure, surgery included aortic valve replacement (7 cases), mitral valve replacement (2), valve repair by suture (7) and repair of Valsalva sinus fistula (6 cases). Two patients died in the early postoperative period and two during follow-up (1-10, mean 4.5 years). The early and the late mortality were related to large infracristal VSD, pulmonary hypertension and irreversible pulmonary vascular changes which could not be anticipated on the basis of high calculated shunt flow at preoperative catheterization. No patient with supracristal VSD died. Recurrent VSD was diagnosed in five patients, three of whom needed reoperation and recovered uneventfully. Reduction of heart size and improved exercise tolerance were the most pertinent follow-up findings. The results suggest that large supracristal VSD with aortic valve involvement can be successfully closed in adults, but that the prospect for large infracristal VSD is less favourable if correction is postponed until adulthood.     

双心房输注对二尖瓣置换术患者体外循环后肺动脉压的影响

目的 评价双心房输注对二尖瓣置换术患者体外循环后肺动脉压(PAP)的影响.方法 择期行二尖瓣置换术合并肺动脉高压[平均肺动脉压(MPAP)＞50 mm Hg]的患者20例,年龄22～53岁,体重34～57kg,心功能分级Ⅱ或Ⅲ级,随机分为2组(n=10):右心房输注组(R组)和双心房输注组(B组).麻醉诱导后右颈内静脉穿刺置入Swan-Ganz三腔漂浮导管,监测CVP、PAP、肺毛细血管楔压(PCWP)和CO.R组经中心静脉输注前列腺素E130～150 ng·kg-1·min-1和去氧肾上腺素0.2～0.6μg·kg-1·min-1.B组经中心静脉输注前列腺素E130～150 ng·kg·min-1,经左心房输注去氧肾上腺素0.2～0.6μg·kg-1·min-1.分别于给药前5 min(T0)、给药后5 min(T1)、10 min(T2)、30 min(T3)和60 min(T4)时记录MAP、HR、MPAP、PCWP、CVP和CO,计算肺血管阻力指数(PVRI)、体循环血管阻力指数(SVRI)和CI.结果 与T0时比较,R组T1-4时MAP、MPAP、PCWP和PVRI降低,CI升高(P＜0.05),HR、CVP和SVRI差异无统计学意义(P＞0.05),B组T1-4时MAP、CI和SVRI升高,HR、MPAP、PCWP、CVP和PVRI降低(P＜0.05);与R组比较,B组MAP、CI和SVRI升高,HR、MPAP、PCWP、PVRI和CVP降低(P＜0.05).结论 双心房输注可降低二尖瓣置换术患者体外循环后肺动脉压和肺血管阻力.     

Haemodynamic Results of Aortic Valve Replacement with the Kay-Shiley Disc Valve

Thirty-nine patients, operated on 8 to 14 months previously with replacement of the aortic valve by a disc valve (Kay-Shiley), were subjected to a postoperative follow-up investigation including right and left heart catheterization. Pre-operatively, aortic stenosis was present in 14 cases, aortic insufficiency in 8, combined stenosis and insufficiency in 15 and an associated mitral stenosis in 2 cases.

Physical working capacity (W₁₅₀) was unchanged, while exercise tolerance (W_max) was significantly increased after operation (from 460 to 670 kpm/min). Cardiac output in relation to oxygen uptake was lower than normal pre-operatively and was unchanged postoperatively. Left ventricular pressures diminished significantly; the peak systolic pressure decreased from 210 to 157 mmHg at rest and from 241 to 172 mmHg during exercise, and the end-diastolic pressure from 23 to 13 mmHg at rest and from 32 to 19 mmHg during exercise. Left atrial (or PCV) mean pressure decreased from 17 to 10 mmHg at rest and from 31 to 16 mmHg during exercise.

Systolic pressure differences across the prosthesis were observed in all patients. The peak pressure difference at rest was in average 28 mmHg and increased to 37 mmHg during exercise. The mean pressure difference averaged 24 mmHg at rest and 31 mmHg during exercise.

The calculated orifice area of the prosthesis, according to the Gorlin formula, averaged 1.36 (±0.3) cm² at rest and 1.54 (± 0.4) cm² during exercise, and was in average 64% of the actual orifice area.

The improvement of cardiac function observed postoperatively is explained by a reduction of cardiac work in combination with a higher distensibility of the left ventricle, leading to decreased pressures in the left atrium and pulmonary circulation.     

The impact of pulmonary valve replacement after tetralogy of Fallot repair: a matched comparison.

OBJECTIVE: While there are no controlled studies, pulmonary valve replacement (PVR) after late tetralogy of Fallot repair is performed for patients with symptoms, arrhythmia or ventricular dysfunction. We sought to determine the impact of PVR on clinical outcomes. METHODS: In a matched cohort study, 82 patients with PVR after tetralogy of Fallot repair without a history of ventricular arrhythmia were matched and compared with similarly followed non-PVR control subjects. A propensity-score adjusted analysis using repeated measures regression techniques was performed. RESULTS: For the PVR subjects, the mean age was 28 years with a mean duration follow-up of 9 years. Before PVR, these subjects were significantly more likely than matched non-PVR subjects to have had non-ventricular arrhythmias, symptoms, lower functional class, longer QRS duration, lower right ventricular ejection fraction and higher right ventricular pressure, and reduced exercise duration but not aerobic capacity. During follow-up, sudden death occurred in four non-PVR subjects compared with no PVR subjects, with three episodes of ventricular tachycardia in the PVR subjects versus none in the non-PVR subjects (p=0.49). Symptoms and functional class improved in the PVR subjects with no change in the non-PVR subjects (p<0.001). The change in QRS duration was not significantly different between PVR and non-PVR subjects (p=0.48). Oxygen consumption at peak exercise did not significantly change in either group. For PVR subjects, there was a significant qualitative reduction in pulmonary (p<0.001) and tricuspid valve regurgitation (p=0.009) and right ventricular size (p<0.001) and dysfunction (p<0.001) noted on echocardiography. CONCLUSIONS: Symptoms and functional status are improved after late PVR, with a reduction in pulmonary and tricuspid valve regurgitation and right ventricular size and dysfunction. While a significant impact on arrhythmia was not detected, there were no sudden deaths in the PVR subjects.     

Open mitral commissurotomy for recurrent mitral stenosis after closed commissurotomy

We evaluated the long-term results in 43 patients who had undergone open mitral commissurotomy for recurrent mitral stenosis after closed commissurotomy. There was one operative death (2.3 percent) and one case of reoperation (2.3 percent). Twenty patients (42 percent) were in NYHA Class I and 22 patients (51 percent) in Class II. In 12 randomly selected patients subjected to postoperative cardiac catheterization, the pulmonary arterial mean pressure remained high at rest and increased to 48 mmHg (mean) during exercise with significant differences in patients who underwent open mitral commissurotomy in the first operation (control group). The left atrial mean pressure was significantly high at rest and rose to 27 mmHg (mean) during exercise. The pulmonary vascular resistance also increased during exercise, with significant differences for the control group. We conclude from these studies that the less satisfactory clinical improvement in patients undergoing reoperation apparently was related to advanced pathology of the mitral valve and development of pulmonary vascular disease.     

Open mitral commissurotomy for recurrent mitral stenosis after closed commissurotomy

We evaluated the long-term results in 43 patients who had undergone open mitral commissurotomy for recurrent mitral stenosis after closed commissurotomy. There was one operative death (2.3 percent) and one case of reoperation (2.3 percent). Twenty patients (42 percent) were in NYHA Class I and 22 patients (51 percent) in Class II. In 12 randomly selected patients subjected to postoperative cardiac catheterization, the pulmonary arterial mean pressure remained high at rest and increased to 48 mmHg (mean) during exercise with significant differences in patients who underwent open mitral commissurotomy in the first operation (control group). The left atrial mean pressure was significantly high at rest and rose to 27 mmHg (mean) during exercise. The pulmonary vascular resistance also increased during exercise, with significant differences for the control group. We conclude from these studies that the less satisfactory clinical improvement in patients undergoing reoperation apparently was related to advanced pathology of the mitral valve and development of pulmonary vascular disease.     

Long-term results of mitral valve surgery in patients with severe pulmonary hypertension

Mitral valve surgery was performed in 88 patients with severe pulmonary hypertension (average systolic pulmonary artery pressure, 94.7 +/- 22 mm Hg; range, 70-180 mm Hg) over a 10-year period. Sixty-four patients (73%) were in New York Heart Association Functional Class III or IV. There were 64 valve replacements and 24 open mitral commissurotomies. Operative mortality was 5.6% (5 patients) and was not related to the degree of pulmonary hypertension, surgical procedure performed, or type of valve lesion. A 100% follow-up was obtained, ranging from nine months to 10 years, with a mean of 44 months. Six late cardiac deaths (7.2%) occurred, 5 in patients with valve replacement and 1 in a patient who underwent a commissurotomy. Actuarial survival was 86 +/- 3% at five years and 83 +/- 4% at 10 years. Fourteen patients underwent right ventricular catheterization a mean of 24 months following operation. Systolic pulmonary artery pressure had decreased from a mean preoperative value of 101 +/- 22 to 40.5 +/- 7 mm Hg (p less than 0.001). Cardiac index increased by 55% of the preoperative values. Functional status improved markedly; 71 survivors (93%) were in New York Heart Association Class I or II. These results indicate that, in patients with mitral valve lesions and severe pulmonary hypertension, (1) surgical procedures can be performed with an acceptable operative mortality; (2) excellent long-term survival and functional results can be obtained; and (3) pulmonary hypertension decreases significantly after operation.(ABSTRACT TRUNCATED AT 250 WORDS)     

A comparison of the acute hemodynamic effects of inhaled nitroglycerin and iloprost in patients with pulmonary hypertension undergoing mitral valve surgery.

BACKGROUND: Since the presence of pulmonary hypertension (PHT) affects the prognosis of the patients, it is important to manage and evaluate PHT. The aim of this study was to compare the hemodynamic effects of inhaled nitroglycerin and iloprost during early postoperative period, in patients with PHT undergoing mitral valve replacement surgery. MATERIALS AND METHODS: One hundred patients with PHT (mean pulmonary artery pressure (MPAP) >25 mmHg at rest), were randomized to receive either inhalation of nitroglycerin (group I; n=50) or iloprost (group II; n=50) in the postoperative period. In both groups, baseline hemodynamic parameters were recorded before the treatment (T(0)). Then, patients in group I received 20 microg.kg(-1) nitroglycerin and those in group II received 2.5 microg.kg(-1) iloprost. The same parameters were recorded immediately after the end of the treatment (T(1)). RESULTS: In both study groups MPAP and pulmonary vascular resistance (PVR) were found to be significantly lower at T(1) when compared to that of T(0) period (p<0.05). MPAP and PVR were significantly lower and mean arterial pressure (MAP) was significantly higher in group II when compared to group I at T(1) period (p<0.05). In addition to decreases in PVR and MPAP, iloprost also increased cardiac output (CO)(4.9+/-1.3 vs 5.1+/-0.9, p<0.05) and stroke volume (SV)(48+/-13 vs 56+/-13, p<0.05). CONCLUSION: Inhaled iloprost and nitroglycerin, both effectively reduce MPAP and PVR without affecting MAP, systemic vascular resistance (SVR) and CO. However, iloprost seems to be a more powerful pulmonary vasodilator, therefore we suggest iloprost inhalation in patients with severe PHT.     

Effect of nitroglycerin inhalation on patients with pulmonary hypertension undergoing mitral valve replacement surgery

BACKGROUND: The aim of this study was to investigate the postoperative hemodynamic effects of nitroglycerin inhalation on patients with pulmonary hypertension undergoing mitral valve replacement surgery. METHODS: Twenty patients who underwent mitral valve replacement surgery were included in the study. In the surgical intensive care unit, at T0 (before the inhalation of nitroglycerin), basal systemic and pulmonary hemodynamics were recorded. Then, 2.5 microg x kg-1 x min-1 nitroglycerin liquid nebulized by a 2-l gas flow of 40% oxygen and air mixture was administered to the patients who were diagnosed as having pulmonary hypertension (mean pulmonary arterial pressures > 25 mmHg). The same parameters were measured at the first (T1), third (T2), and fifth (T3) hours after the beginning of this treatment and 1 h after the end of nitroglycerin inhalation (T4). RESULTS: There were no statistically significant differences at T0, T1, T2, T3, or T4 with respect to heart rate, mean arterial pressure, systemic vascular resistance, cardiac index, mixed venous oxygen saturation, arteriovenous oxygen content difference, or arterial carbon dioxide tension. However, mean pulmonary artery pressure, pulmonary vascular resistance, and intrapulmonary shunt fraction were significantly lower, and the arterial oxygen tension/fraction of inspired oxygen ratio was higher at T1, T2, and T3 when compared to that of T0 and T4. CONCLUSION: The results suggest that nitroglycerin inhalation produces a significant reduction in both mean pulmonary artery pressure and pulmonary vascular resistance in patients after mitral valve operations without reducing mean arterial pressure and systemic vascular resistance. Therefore, it might be a safe and useful therapeutic intervention during the postoperative course.     

Successful treatment of a patient with severe pulmonary hypertension due to perivalvular leakage at aortic and mitral positions after aortic and mitral valve replacement

A 33-year-old-man had severe secondary pulmonary hypertension due to perivalvular leakage at the aortic and mitral positions after aortic and mitral valve replacement. Preoperative cardiac catheterization revealed pulmonary artery pressure of 105/45 mmHg and pulmonary vascular resistance of 929 dynes.s.cm(-5) To save the patient, we performed aortic and mitral valve re-replacement, and tricuspid annuloplasty. After surgery, selective pulmonary vasodilators, beraprost sodium, inhaled nitric oxide, and intravenous prostaglandin (PG) I(2) were administered because of persistent severe pulmonary hypertension. Cardiac catheterization on postoperative day 58 showed that the pulmonary artery pressure and pulmonary vascular resistance had decreased to 40/20 mmHg and 87.7 dynes x s x cm(-5), respectively The simultaneous use of inhaled nitric oxide, intravenous PGI(2), and oral beraprost sodium might be useful for treating postoperative persistent pulmonary hypertension.