ABSTRACT
BACKGROUND: This study was carried out to determine the vasodilator response of inhaled nitric oxide in patients with pulmonary hypertension (PH) after valve replacement surgery for mitral valve disease. METHOD: This Quesi experimental study was carried out at the intensive care unit of Armed Forces Institute of Cardiology (AFIC) in collaboration with Department of Physiology, Army Medical College, Rawalpindi from March 2004 to February 2006. Thirty patients with systolic Pulmonary Artery Pressure (PAP) > 50 mmHg on pre-operative echocardiography were inducted. Swan Ganz catheter was inserted to record baseline pulmonary artery pressure and pulmonary capillary wedge pressure (PCWP), while cardiac output (CO) was recorded through lithium dilution method. Pulmonary Vascular Resistance (PVR) was calculated with the help of a formula. Inhaled nitric oxide (iNO) was administered after the surgery and the same parameters were recorded again after one hour. RESULTS: The majority of patients were females (73%), while males were only 27%. Out of 30, 21 had isolated mitral stenosis and 9 had mixed mitral and aortic valve disease. 22 patients responded significantly to iNO therapy with > or = 40.0% reduction in their baseline PVR while 8 patients showed insignificant improvement in their PVR (663 +/- 233 dynes.sec.cm(-5) to 605 +/- 222 dynes.sec.cm(-5)). CONCLUSION: Significant improvement in pulmonary vascular resistance in the responders and maintenance of high pressures despite iNO therapy in non-responders indicate that apart from some abnormality in nitric oxide pathway, some other factors may be a contributing in the causation of PH secondary to mitral stenosis in adults, which warrant further studies.
Subject(s)
Bronchodilator Agents/therapeutic use , Endothelium-Dependent Relaxing Factors/therapeutic use , Hypertension, Pulmonary/drug therapy , Mitral Valve Stenosis/surgery , Nitric Oxide/therapeutic use , Postoperative Complications/drug therapy , Administration, Inhalation , Adult , Bronchodilator Agents/administration & dosage , Cardiac Output , Catheterization, Swan-Ganz , Endothelium-Dependent Relaxing Factors/administration & dosage , Female , Heart Valve Prosthesis , Humans , Hypertension, Pulmonary/physiopathology , Male , Mitral Valve/pathology , Mitral Valve/surgery , Nitric Oxide/administration & dosage , Postoperative Complications/physiopathology , Pulmonary Wedge Pressure/drug effects , Vascular Resistance/drug effects , Vasodilation/drug effectsABSTRACT
OBJECTIVE: To identify the factors affecting the outcome, measured in terms of morbidity and mortality, after primary ventricular septal defect (VSD) closure. DESIGN: Descriptive study. PLACE AND DURATION OF STUDY: Armed Forces Institute of Cardiology/National Institute of Heart Diseases, Rawalpindi, from January 2002 to October 2003. SUBJECTS AND METHODS: Children upto the age of 5 years who had primary VSD closure were studied. Patients were divided into two groups. Group-I included survivors and group-II included non-survivors. There was no difference in the conduct of operation among the two groups. RESULTS: A total of 53 patients were operated of whom 47 survived. Pulmonary hypertensive crisis (p < 0.001), pulmonary infections (p < 0.001) and pleural effusions (p < 0.003) were higher in non-survivor group. Patients in non survivor group were younger (0.75 + 0.34 years vs 2.24 + 1.16 years, p = 0.01) having less body weight (4.91 + 1.56 kg vs 7.94 + 3.35, p = 0.03) and high pulmonary artery to systemic pressure ratio at the time of coming off bypass (0.63 + 0.13 vs 0.43 + 0.09, p < 0.001). Non survivors had higher association (66.6 % vs 19.1%) of additional left to right shunts (p < 0.001). CONCLUSION: Body weight less than 5 kg along with young age, high pulmonary artery to systemic pressure ratio at the time of coming off bypass and presence of additional left to right shunt are risk factors for adverse outcome.
