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F Isobe

Publications and source records attributed to F Isobe.

At least 37 records · Page 2Linked to original sources
PubMed1996

Factors affecting rhythm after the maze procedure for atrial fibrillation.

BACKGROUND: The maze procedure failed to abolish atrial fibrillation (AF) in 14% of patients with underlying organic cardiac lesions. Identification of contributing risk factors will improve results either by treatment of such factors or by avoidance of high-risk patients. METHODS AND RESULTS: We analyzed 192 consecutive patients with AF undergoing three variations of the maze procedure performed simultaneously with correction of valvular diseases (n = 165), congenital anomalies (n = 19), isolated AF (n = 7), and ischemic disease (n = 1). Twenty-six preoperative factors and two postoperative cardiac size parameters were analyzed by multivariate analyses between patients with successfully ablated AF (n = 165) and those who remained in AF (n = 27) after the maze procedure. Among all factors, postoperative left atrial dimension was the most potent in predisposing patients to persistent AF. Duration of AF left atrial dimension, and cardiothoracic ratio were identified as preoperative risk factors, whereas modifications of the maze procedure and pathogenesis and location of underlying disease failed to have a significant prognostic impact on rhythm after surgery. Individual risk analysis using the three preoperative variables revealed that left atrial size reduction to normalize its dimension played a pivotal role in determining rhythm after the maze procedure. CONCLUSIONS: Results favor earlier performance of the procedure before these risk factors develop, after which omission of the procedure or extensive left atrial plication may be appropriate. This requires further study.

Adolescent↗
PubMed1996

Rationale of the Cox maze procedure for atrial fibrillation during redo mitral valve operations.

OBJECTIVE: The frequency of reoperation for mitral valve diseases with chronic atrial fibrillation has increased steadily. This study examined the rationale for using the Cox maze operation for atrial fibrillation during redo mitral valve operations. METHODS: Between June 1992 and July 1995, we performed the maze procedure in 42 patients as a concomitant operation with redo mitral valve surgery (maze group). Associated procedures were tricuspid valve surgery in 27 patients and aortic valve surgery in 15 patients. The mean age at operation was 57.3 +/- 9.7 years, and the mean interval from the previous operation was 14.3 +/- 10.5 years. The mean follow-up period after the maze procedure was 25.5 +/- 10.8 months. Atrial fibrillation was present at the time of the previous operation in 29 patients (69%). RESULTS: Neither hospital death nor late death occurred. Sinus rhythm was regained in 28 patients (67%), and an atrial A-wave was detected in 21 patients (50%) by pulsed Doppler study. Patients in whom sinus rhythm was restored had a shorter history of atrial fibrillation (9.0 +/- 6.0 years vs 15.9 +/- 4.6 years, p = 0.0009), a larger f-wave on lead V1 of the electrocardiogram (0.18 +/- 0.10 mV vs 0.10 +/- 0.08 mV, p = 0.017), and a smaller cardiothoracic ratio (63% +/- 8% vs 67% +/- 5%, p = 0.049) than patients with persistent atrial fibrillation. During the same period, 54 patients underwent mitral valve reoperation without the maze procedure (control group). The aortic crossclamp and cardiopulmonary bypass times were slightly longer (p = 0.048 and p = 0.012) in the maze group (133 +/- 28 minutes and 221 +/- 43 minutes) than in the control group (126 +/- 65 minutes and 197 +/- 78 minutes). There was no significant difference in the amount of chest tube drainage or transfusion between the two groups (890 +/- 510 ml and 2120 +/- 1600 ml, respectively, in the maze group and 840 +/- 480 ml and 2140 +/- 1760 ml, respectively, in the control group). It was not necessary to reopen the chest for bleeding significantly more often in one group than in the other (14% in the maze group and 7% in the control group), and it was possible to operate without transfusion with the same frequency in the two groups (17% in the maze group and 20% in the control group). CONCLUSION: These results suggest that the maze procedure should be considered in selected patients who have a high possibility of regaining sinus rhythm during redo mitral valve operations.

Adult↗
PubMed1996

Ten-year experience with the Carpentier-Edwards pericardial xenograft in the tricuspid position.

We reviewed the cases of 66 patients who underwent 67 tricuspid valve replacements with Carpentier-Edwards pericardial xenografts between April 1985 and January 1994. Average patient age at time of operation was 52 years (range 8 to 71 years). Concomitant mitral or aortic valve replacements were performed in 46 patients. There were 10 operative deaths and 6 late deaths. Actuarial survival at 9 years was 75.4% +/- 5.7%. Prosthetic valve endocarditis occurred twice in one patient. Reoperations for tricuspid regurgitation and for concomitant procedures (maze operation and repair for leak of the mitral prosthesis) were performed in two patients. In both cases, examination of the explanted prostheses showed that the tricuspid regurgitation was the result of nonstructural dysfunction caused by fibrous pannus formation on the cusps of the ventricular side. Among the survivors, 47 patients (92%) were in functional class I or II. Prosthetic valve function was studied by color Doppler echocardiography. Among 38 patients, tricuspid regurgitation more than grade 3/4 or transprosthetic gradient more than 5 mm Hg was found in 11. One patient had right heart failure and the others had no symptoms. In 10 years of experience with the Carpentier-Edwards pericardial xenograft, mortality and morbidity after tricuspid valve replacement were satisfactory. Echocardiographic examination revealed subclinical prosthetic dysfunction in 35% of patients who were followed up for longer than 5 years, however, and we believe that these patients should receive careful follow-up.

Adolescent↗
PubMed1996

Surgical stratification of patients with atrial fibrillation secondary to organic cardiac lesions.

BACKGROUND: While the maze procedure does not always eliminate atrial fibrillation (AF) secondary to organic cardiac lesions, concomitant performance of the procedure is associated with increased surgical complexity and potential risks. METHODS: To stratify the surgical approach for patients with AF secondary to underlying cardiac lesions, we analyzed 24 preoperative and perioperative variables in 115 consecutive patients with AF undergoing a modified maze procedure combined with valvular intervention (101), repair of congenital anomalies (13) and coronary revascularization (1). RESULTS: Patients who remained in AF (18) compared to patients with restored atrial rhythm (97), had a higher incidence of giant left atrium (56% vs 10%, P < 0.0001), larger cardiothoracic ratio (70 +/- 13 vs 62 +/- 8%, P = 0.001) and left atrial dimension (64 +/- 12 vs 55 +/- 12 mm, P = 0.004), a longer history of AF (13.7 +/- 6.8 vs 8.3 +/- 6.9 years, P = 0.003) and lower f-wave voltage (0.10 vs 0.15 mV, P = 0.004). Multivariate logistic regression analysis of 24 preoperative and perioperative variables identified the presence of giant left atrium, cardiothoracic ratio and age at operation as the significant risk factors predisposing patients to persistent postoperative AF. Retrospective estimation identified 73 (63.5%) patients with a high probability of atrial defibrillation (97.3%) and 42 (36.5%) patients with a high risk of failure (38.1%). Regardless of the preoperative risk analysis or the performance of left atrial plication, every patient with a postoperative left atrial dimension less than 40 mm or cardiothoracic ratio below 55% was successfully defibrillated. CONCLUSION: The results suggest performing the maze procedure before "risk factors" develop for patients with predicted maze-amenable AF. While omitting the maze procedure may be prudent for patients with suspected maze-refractory AF, the simultaneous reduction of left atrial size may offset the increased risk from preoperative size factors. A prospective study seems warranted to examine the effects of left atrial plication on postoperative rhythm.

Adult↗
PubMed1996

QRS alteration-induced torsade de pointes in a patient with an artificial pacemaker and hypokalemia.

The present patient demonstrated torsade de pointes (TdP) after a pacemaker implantation without a decrease in heart rate or pacemaker malfunction. Marked QT prolongation and TdP were closely related to alteration of the depolarization pattern (appearance of junctional rhythm). Resetting the pacemaker to a rate that inhibited spontaneous rhythm was effective in preventing TdP.

Electrocardiography↗
PubMed1996

[Valvular surgery in the patients more than 70 years old].

One hundred twenty-eight valvular surgeries in patients over 70-year-old were reviewed (AVR:58, MVR:38, AVR and MVR: 11, mitral valvuloplasty (MVP): 11, AVR + MVP:11, mitral valvuloplasty (MVP): 11, AVR + MVP: 8, others: 2). Concomitant CABG was performed in 7, Maze in 6, TVR in 5 and Bentall in 3 cases. Early deaths occurred in 17 patients (13%). The early mortality was 5% in AVR, 21% MVR, 18% in AVR and MVR, 0% in MVP and 38% in AVR and MVP. Late death occurred in 16 patients. Forty-three percent of the late deaths were cardiac death. The actuarial survival at 10 years was around 50% in all groups. In the aortic position, a mechanical valve was implanted in 47 cases and a bioprosthetic valve was implanted in 33 cases. In the mitral position, the mechanical valve was implanted in 37 cases and the bioprosthetic valve was implanted in 12 cases. The event free rate after AVR at 10 years was 37% in patients with the mechanical valve (3 cerebral hemorrhage, 2 PVE, 1 thromboembolism and 1 sudden death) and 46% in patients with the bioprosthetic valve (2 PVE and 1 primary tissue failure). The event free rate after MVR at 10 years was 84% in patients with mechanical valves (1 perivalvular leak, 1 PVE and 1 sudden death) and 75% in patients with bioprosthetic valves (1 PVE and 1 sudden death). Between mechanical valve group and bioprosthesis group, no statistically significance was found in the event free curve after AVR nor MVR. There was no valve related event after MVP. Considering the better durability of bioprostheses in the aortic position than in the mitral position, the presence of atrial fibrillation and necessity of warfarin anticoagulation, we conclude that a choice of a bioprosthetic valve could be acceptable in the aortic position, but may not be recommended in the mitral position.

Aged↗
PubMed1996

Valve replacement with the CarboMedics bileaflet mechanical prosthesis: clinical results at midterm.

OBJECTIVE: We study the clinical midterm results of the valve replacement with the CarboMedics bileaflet mechanical prosthesis. EXPERIMENTAL DESIGN AND SETTING: Retrospective study. Institutional practice (National Cardiovascular Center, Osaka, Japan). PATIENTS AND INTERVENTIONS: 167 CarboMedics prostheses were implanted in 144 patients from April, 1990 and December, 1993. Of these, 77 patients underwent isolated aortic valve replacement (AVR), 45 patients underwent isolated mitral valve replacement (MVR), 21 patients underwent double (aortic and mitral) valve replacement (DVR), and one patient underwent triple (aortic, mitral and tricuspid) valve replacement (TVR). MEASURES: Events were defined in accordance with the guidelines for reporting morbidity and mortality after cardiac valve operations of the Society of Thoracic Surgeons/American Association for Thoracic Surgery.

Aortic Valve↗
PubMed1996

[Anticoagulant related hemorrhage and thromboembolism after valvular surgery].

We reviewed anticoagulant related hemorrhage (ACRH) and thromboembolism (TE) in 84 patients after valvular surgery. There were 45 females and 39 males with a mean age of 51.8 years (range 30.5-71.2 years), who underwent valvuloplasty in 14, bioprosthetic valve replacements in 17, mechanical valve replacements in 13. A mean period from the operation to the event were 2.7 years (range 0.01-12.3 years). There were 25 ACRH events after one valvuloplasty, 4 bioprosthetic valve replacements, 20 mechanical valve replacements. About half of them, the prothrombin time were less than 25%, which was considered the effect of warfarin is high, and 8% of them had infective endocarditis (IE) previously. There were 59 TE events after 13 valvuloplasties, 13 bioprosthetic valve replacements, 33 mechanical valve replacements. In the patients with atrial fibrillation, TE occurred irrespective of operative procedures. And in the patients with mechanical valve, severely impaired left ventricular function and past history of IE, thrombi of left ventricule were caused of TE. It was suggested that past history of IE was a risk factor ACRH and TE, and severely depressed left ventricular function and atrial fibrillation were for TE.

Adult↗
PubMed1996

Aortic and mitral valve replacement with the Carpentier-Edwards pericardial bioprosthesis: 10-year results.

BACKGROUND AND AIM OF THE STUDY: This report reviews our experience with single aortic and mitral valve replacement using the Carpentier-Edwards pericardial valve in a population younger than those of other reports. METHODS: Between 1984 and 1993, 106 patients underwent single aortic or mitral valve replacement using a Carpentier-Edwards pericardial valve. There were 49 aortic and 57 mitral implants. The mean age was 56.7 +/- 14.3 years. The follow up was 100% complete; total follow up being 273.3 patient-years in the aortic (AVR) and 348.0 patient-years in the mitral valve replacement (MVR) group, with a mean of 5.6 and 6.1 years, respectively. RESULTS: The rates of thromboembolic complications for AVR and MVR were 0.37% and 0.58% per patient year respectively. There were no cases of non-structural dysfunction or anticoagulant-related hemorrhage. The incidences of prosthetic valve endocarditis for AVR and MVR were 0% and 0.86% per patient year respectively. Structural deterioration (calcification and sclerosis) occurred in one patient after AVR and in six patients after MVR, all younger than 60 years of age. Freedom from structural deterioration at five years and 10 years was 100% and 92.9% +/- 6.9% for AVR, and 100% and 76.9% +/- 8.6% for MVR. CONCLUSIONS: In conclusion, the Carpentier-Edwards aortic valve has a low incidence of valve-related complications at 10 years. Although late results of this valve in the mitral position were excellent in the elderly, leaflet degeneration is still a problem in patients under the age of 60 years.

Adult↗
PubMed1996

[Clinical study of re-do surgery after Bentall-type operation].

Among patients who underwent reconstruction of the aortic root by Bentall-type procedure using a composite graft, we investigated patients who underwent reoperation for complications related to composite graft. We employed composite graft reconstruction of the aortic root in 155 patients for 16 years prior to December 1994. Annulo-aortic ectasia was observed in 112 patients, aortic dissection in 34, and aortitis without aneurysm formation in 9. The original Bentall procedure was performed in 36, the Cabrol method in 8, the interposition method in 26, and the Carrel patch method in 85 patients. Thirteen (8.4%) of these patients required reoperation for complications related to the composite graft. Three of 4 patients with graft infection early after surgery underwent reconstruction with composite graft, but died in the hospital. The remaining patient survived after combined treatment that included the graft washing with Iodine (Isozin) solution and omentopexy. Four patients developed pseudoaneurysm formation due to sutural insufficiency and 7 has prosthetic valve failure as late complications. Three of the 4 patients with pseudoaneurysm underwent reconstruction with a second composite graft by the interposition method, while one patient with aortitis required another reoperation. In the remaining one patient, the leak was directly close along with second aortic valve replacement. All prosthetic valves used in 7 patients with prosthetic valve failure were Ionescu-Shiley biological valves. Primary tissue failure was observed in 6 and prosthetic valve endocarditis in one patient. Second cardiac valve replacement using a mechanical valve was possible. All the patients who underwent late reoperation showed favorable results. Infection of the composite graft showed the poor prognosis, and prevention of infection is important. Sutural insufficiency at the anastomosed site can be prevented by appropriate surgical procedures such as reinforcing suture, but further countermeasures for sutural insufficiency were considered necessary for aortitis in conditions, such as Behcet's diseases.

Adult↗
PubMed1995

Modified maze procedure for patients with atrial fibrillation undergoing simultaneous open heart surgery.

BACKGROUND: Persistent atrial fibrillation (AF) leaves patients symptomatic and at increased risk of thromboembolism even after otherwise successful cardiac surgery. METHODS AND RESULTS: To treat AF secondary to cardiac lesions requiring surgery, we combined a modified maze procedure in 101 patients simultaneously undergoing valvular procedures (87), repair of congenital anomalies (12), and other procedures (2), including 24 repeat operations. Duration of AF varied from 0.1 to 30 years (average +/- SD, 8.8 +/- 7.0 years); the f-wave voltage ranged from 0 to 0.45 mV (0.15 +/- 0.09 mV); and cardiothoracic ratio varied from 40% to 99% (63 +/- 9%). Aortic cross-clamp time varied from 75 to 229 minutes (138 +/- 31 minutes), with bypass time ranging from 119 to 326 minutes (217 +/- 42 minutes). There were two early deaths (2%), no late deaths, and one episode of transient neurological ischemic attack in follow-up ranging from 1.0 to 3.1 years, for a total of 190 patient-years. Postoperative rhythms were sinus in 83 patients (82%), junctional in 4 (4%), and persistent AF in 14 (14%), each of whom had mitral valve disease. Patients with other underlying pathology had complete recovery of atrial rhythm. A normal-sized A wave was detected in 88% for transtricuspid flow and in 73% for transmitral flow, suggesting concomitant recovery of atrial contraction. Among 36 patients without mechanical valves, 30 (83%) with atrial rhythm and contraction have been taken off anticoagulation therapy, including 10 who are free of all medication. CONCLUSIONS: The results suggest that the combined approach is safe, effective, and indicated in patients who are judged capable of tolerating the procedure and likely to regain atrial rhythm.

Aged↗
PubMed1995

Extent of aortopulmonary collateral blood flow as a risk factor for Fontan operations.

Between November 1987 and January 1990, 33 patients (tricuspid atresia, 9 patients; mitral atresia, 3; single ventricle, 15; others, 6) underwent Fontan operations. The rate of blood flow returning to the heart during aortic cross-clamping was measured as an indication of the extent of development of aortopulmonary collateral arteries. Percent cardiac return (calculated by dividing the blood flow rate returning to the heart by the cardiopulmonary bypass blood flow rate and expressing the value as a percentage), were 1% to 9%, 7 patients; 10% to 19%, 11; 20% to 29%, 9; 30% to 39%, 4; 40% to 49%, 1; and 50% to 59%, 1 patient. Percent cardiac return showed a significant correlation with postoperative mean systemic venous pressure (r = 0.6, p < 0.01). In those patients in whom percent cardiac return was more than 33%, the mean systemic venous pressure after operation was high (more than 17 mm Hg), and none of these patients survived. To predict percent cardiac return preoperatively, the conventional indices of systemic ventricular volume, pulmonary artery area index, arterial blood oxygen saturation, pulmonary blood flow index, and pulmonary vascular resistance were analyzed. None of these showed significant correlation with percent cardiac return. However, all the patients who had a high percent cardiac return (more than 30%) also had both high arterial blood oxygen saturation (more than 75% in room air) and small pulmonary artery area index (less than 55%). In addition, the age at operation showed good correlation (r = 0.6, p < 0.01) to percent cardiac return.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Biventricular repair in cardiac isomerism. Report of seventeen cases.

Ninety-three patients with cardiac isomerism were treated surgically from July 1985 to June 1991. Among them, three patients with right and 14 with left isomerism underwent biventricular repair. Ages ranged from 4 months to 41 years (mean 4.8 years). Anatomic repair was accomplished in 15 patients and functional repair with the right ventricle used as the systemic ventricle in two patients. Methods of atrial septation to separate pulmonary venous flow from systemic venous flow included atrial partition with a straight patch in seven patients, intraatrial rerouting with a tailored baffle in five, and a Mustard-type atrial switch in five. One hospital death (5.8%) and two late deaths (12%) occurred. Two patients required reoperation (12%), one reconstruction of a stenotic systemic venous connection and one mitral valve replacement because of incompetence. Surgically induced complete atrioventricular block was not observed in any of the patients. Optimal atrial septation offers the possibility of biventricular repair for patients with acceptable intraventricular structure.

Abnormalities, Multiple↗
PubMed1995

[Surgical treatment and long-term results of cardiac myxoma in 38 patients].

Long-term results of thirty-eight patients with cardiac myxoma, who underwent resection at National Cardiovascular Center between May, 1978 and December, 1993, were reviewed focussing on embolism, cerebral complication, tumor recurrence and metastasis. The mean age was 49.6 years (range 0 to 74) in 20 female and 18 male. Overall follow-up were known for 35 of 38 patients (92.1%), and an average of follow-up period was 6.7 years (range 0.5 to 15.9 years). 15 of 38 patients (34.2%) had embolism (brain 10, peripheral artery 4, coronary 1) preoperatively. All patients survived operation and the hospital mortality rate was 0%. Long-term results were almost satisfactory (myxoma related-death in one patients). However, distant metastasis occurred in two patients, and tumor recurrence in one patient irrespective of a presence of preoperative embolism. Cerebral embolism occurred in one patient and cerebral arterial lesins were noticed in five patients postoperatively. Cardiac myxoma has a malignant potentiality and a close follow-up is necessary about recurrence, metastasis and cerebral artery disease.

Adolescent↗
PubMed1995

[Results of coronary artery bypass grafting in dialysis patients].

To determine the short- and medium-term results of coronary artery bypass grafting (CABG) in dialysis patients, we analyzed a group of 14 patients with chronic renal failure who underwent CABG between May 1990 and October 1994. Two patients had concomitant valve repair for mitral regurgitation. Hospital mortality was 14% (2 out of 14). These two patients died of ileus due to ischemic colitis and agranulocytosis respectively. There was one late death from stroke. The four significant postoperative complications (morbidity 29%) were composed of two sternal dehiscence, one cardiac tamponade because of bleeding, and one perioperative myocardial infarction. Graft patency rate was 97% (34 out of 35 in 13 patients) within one month. Actuarial survival was 86% at one 1 to 3 years, and 43% at 3 and a half years. This rate is not significantly different from all dialysis patients, but night be better than dialysis patients with coronary artery disease who had not undergone CABG in the previous reports. Left ventricular size is larger in patients who died or who had significant complications in hospital than in patients with uneventful postoperative course. Cardiac arrest time, cardiopulmonary bypass time, chest tube output, and the amount of transfusion might be also related to mortality and morbidity though statistically not significant.

Aged↗