Shinichiro Yoshimura

β-blocker therapy in patients after aortic valve replacement for aortic regurgitation

BACKGROUND beta-blocker therapy for dilated or ischemic cardiomyopathy is now an accepted and effective treatment. However, little is known about its efficacy in patients with postoperative impaired left ventricular function. This retrospective study was designed to assess the effects of beta-blocker therapy in patients after aortic valve replacement (AVR) for aortic regurgitation (AR). METHODS A total of 59 patients who underwent AVR for chronic AR were assigned to four groups. Twelve patients were treated with both ACE inhibitors and beta-blockers, 12 patients with only ACE inhibitors, eight patients with only beta-blockers, and 27 patients without beta-blockers or ACE inhibitors. A postoperative echocardiographic study was performed one year after surgery. RESULTS The heart rate was significantly reduced in patients with beta-blockers despite the use of ACE inhibitors after surgery. Postoperative left ventricular volume was more significantly decreased in beta patients than in non-beta patients despite the use of ACE inhibitors. There were also significant reductions in left ventricular mass index in ACE+beta patients compared to ACE+non-beta patients. However, there were no significant differences in NYHA functional class and survival rate between beta patients and non-beta patients. CONCLUSIONS beta-blocker therapy may improve cardiac performance by reducing cardiac volume and mass in patients with impaired LV function after AVR for AR.

Methicillin-Resistant Staphylococcus aureus Endocarditis Following Repair of Tetralogy of Fallot

AbstractInfectious endocarditis following cardiac surgery, particularly that caused by methicillin-resistant Staphylococcus, aureus is a rare and highly lethal complication. We report a case of a 2-year-old girl who developed methicillin-resistant S. aureus endocarditis and mediastinitis following the intracardiac repair of tetralogy of Fallot using Dacron patches. The patient enveloped severe bacteremia accompanied by disseminated intravascular coagulation and progressive enlargement of vegetation. Despite this condition, the patient was successfully treated by repair using double autogenous pericardial patches. Aggressive removal of foreign material and replacement with autogenous tissue resulted in a favorable outcome.

Pulmonary venous obstruction requiring lobectomy for hemoptysis after a Glenn operation

Right atrial isomerism is well known to be associated with anomalous pulmonary venous drainage and a potentially dangerous sequel to pulmonary venous obstruction, and is associated with high mortality. We report a 16-month-old girl with pulmonary venous obstruction requiring lobectomy for hemoptysis after a Glenn operation. Two years after surgery, she is doing well with 80% oxygen saturation and no further episodes of hemoptysis.

Coronary artery bypass grafting for patients with an atherosclerotic ascending aorta.

OBJECTIVES We review the outcome of coronary artery bypass grafting in patients with a severe atherosclerotic ascending aorta. METHODS Subjects were 31 patients averaging 69.4 +/- 6.9 years old studied from 1990 through 1998. Ascending aortic lesions were assessed using epiaortic echo and 2 types of aortic nonclamping techniques applied. In 29 patients operated on in the early years, bypass grafting was conducted on the hypothermic fibrillated heart in 22 and on the beating heart in 7. The remaining 2 underwent off-pump coronary artery bypass grafting more recently. For cases with multivessel disease, we used composite grafting. RESULTS Three patients developed mild stroke and 5 died within 30 days of surgery--4 from multiple emboli (1 accompanied by a stroke) and 1 from perioperative myocardial infarction. One hospital death occurred due to brain damage and multiorgan failure following unexpected rupture of a saphenous vein graft. No cardiac deaths occurred in the late stage of our series. Actuarial survival was 73.0% for 3 years and 68.0% for 5 years. Freedom from cardiac events was favorable in the remaining 25 survivors. CONCLUSIONS Outcome was suboptimal for the risks involved. Recent technical advances, including coronary surgery on the beating heart with or without cardiopulmonary bypass using variable in-situ or free arterial grafts, associated with adequate evaluation of systemic atherosclerosis, should improve this outcome.

Myocarditis in a girl with mixed connective tissue disease

A 14-year-old girl presented with Raynaud’s phenomenon and a high anti-U1-ribonucleoprotein (anti-U1-RNP) antibody titer, suggestive of MCTD. She was admitted to hospital with a 4 day history of rapidly worsening high-grade fever, chest pain and general malaise. On physical examination on admission, body height was 150 cm ( 1.3 SD); bodyweight, 40 kg ( 20% of the ideal bodyweight); body temperature, 36.9°C; heart rate, 121 beats/min; and respiratory rate, 35 breaths/min. Although gallop rhythm and hepatomegaly were noted, there was no heart murmur or abnormal respiratory sound on auscultation. Chest X-ray showed cardiomegaly (cardiothoracic ratio [CTR], 64%) and hydrothorax. Electrocardiography showed low voltage on all limb leads and a QS pattern on leads V2–V5. Echocardiography demonstrated marked hypokinesia of the left ventricle (LV) wall and a decreased LV ejection fraction (LVEF) of 22.1%, suggesting myocardial damage. Although tricuspid regurgitation (2.5 m/s) was detected, there was no paradoxical movement of the interventricular septum. Laboratory examination indicated elevated lactate dehydrogenase, 489 IU/L; aspartate aminotransferase, 99 IU/L; creatine kinase (CK), 362 IU/L; brain-type natriuretic peptide (BNP), 2,778.0 pg/mL; troponin T, 0.75 ng/ mL; C-reactive protein, 3.9 mg/dL; and positive anti-U1-RNP antibodies >500 U/L, whereas white blood cell count was 7,900/ lL; hemoglobin, 11.5 g/dL; and platelets, 28.6 9 10/lL. Complement fixation test for antibodies to Coxsackie virus B1, B2, B3, B4, B5 and B6, and mycoplasma pneumoniae was negative. No virus was isolated from the feces or urine. The hemodynamics responded to 3 days of high-dose i.v. immunoglobulin (IVIG, 1 g/kg) and methylprednisolone (mPSL) pulse therapy in combination with continuous infusion of dopamine at 5 lg/kg/min (Fig. 1). Both CTR on chest roentgenogram and LVEF on ultrasonic cardiography gradually recovered even after the cessation of inotropics. T2-weighted magnetic resonance imaging of the heart showed diffuse myocardial signal hyperintensity throughout the entire wall. Myocardial perfusion scintigraphy showed diffuse impairment of wall motion without significant regional hypoperfusion. Pancreatitis developed on the third hospital day but subsided following urinastatin and nafamostat mesilate treatment. The patient was discharged on hospital day 29. One year later, cardiac function is normal (LVEF, 63.4%; BNP, 5.3 pg/mL) on low-dose PSL (5 mg/day) for MCTD.