Junya Kamata

Predictors of sinus rhythm restoration after cox maze procedure concomitant with other cardiac operations

BACKGROUND There have been sporadic cases of persistent atrial fibrillation and sick sinus syndrome after the maze procedure. The purpose of this study was to identify the predictors of sinus rhythm restoration after operation. METHODS Between March 1993 and June 1995, we evaluated retrospectively 96 consecutive patients who underwent the maze procedure (maze III) in combination with another type of cardiac operation. Four patients who died and 6 patients who required permanent pacemaker implantation because of sick sinus syndrome were excluded. Ambulatory electrocardiographic monitoring was evaluated 1 year after operation. Multiple logistic regression analysis was applied to identify the predictors of sinus rhythm restoration. RESULTS The final population comprised 86 patients (mean age, 59.8 years; 67 patients with mitral valve disease). Overall, sinus rhythm was restored in 68 of 86 patients (79.1%). The magnitude of the atrial fibrillatory wave positively predicted postoperative sinus rhythm restoration. Conversely, left atrial diameter was inversely related to postoperative sinus rhythm restoration. The odds ratio of having both a fine atrial fibrillatory wave (< 1.0 mm) and enlarged left atrial diameter (> or = 65 mm) for patients with sinus rhythm restoration was 0.04 (95% confidence interval, 0.01 to 0.28). CONCLUSIONS Atrial fibrillatory wave and left atrial diameter were independent predictors of sinus rhythm restoration after the maze procedure in patients with chronic atrial fibrillation and organic heart disease.

Operative results after the Cox/maze procedure combined with a mitral valve operation

BACKGROUND There have been few reports on postoperative morbidity and mortality analyses after concomitant mitral valve operation and the Cox/maze procedure. METHODS Between April 1993 and August 1995, 87 consecutive patients with chronic atrial fibrillation underwent a mitral valve operation and concomitant Cox/maze procedure at Iwate Medical University. The patients were divided into the replacement group (n = 31) and repair group (n = 56) according to the method of mitral valve replacement. Our initial experience with the combined operative procedures is presented along with the operative mortality and morbidity rates. Univariate analysis on preoperative and intraoperative variables affecting early mortality and morbidity is carried out retrospectively. RESULTS Total cardiopulmonary bypass time in all patients was 177.2 +/- 70.1 minutes. Total aortic cross-clamp time was 121.7 +/- 30.8 minutes. Total intensive care unit stay was 5.3 +/- 7.9 days. The average intubation period was 55.5 +/- 187.6 hours. The intensive care unit stay and the intubation period of the replacement group were longer than those of the repair group. There were four operative deaths among the 87 patients (4.6%). All repair group patients survived operation, whereas 4 replacement group patients died after operation. In all patients, the New York Heart Association functional class was higher (p = 0.028) in those who died than in those who survived. The overall restoration rate from atrial fibrillation was 79.5% (66 of 83 survivors). Seventeen patients (20.5%) had persistent atrial fibrillation postoperatively. Sick sinus syndrome occurred in 7 patients (8.4%). In the repair group, the restoration rate was 76.8%, whereas in the replacement group it was 85.2% for the survivors. CONCLUSIONS The Cox/maze procedure can be combined with a mitral valve operation with acceptably low operative risk. Analysis of risk factors of early mortality revealed that the type of mitral valve operation (replacement versus repair) and higher preoperative New York Heart Association functional class were associated with mortality. Long-term results from this combined procedure should be clearly demonstrated before its universal acceptance.

Medium-term results after the modified Cox/Maze procedure combined with other cardiac surgery

OBJECTIVE Long-term results after the modified Cox/Maze III procedure combined with other cardiac procedure for the treatment of organic heart disease and chronic atrial fibrillation (AF) has not been clarified. This report describes our medium-term results after such operation. METHODS Between March 1993 and August 1995, 104 consecutive patients with chronic AF underwent the modified Cox/Maze III procedure combined with other cardiac procedure. There were 100 long-term survivors. There were 45 men and 55 women, with ages ranging from 21 to 77 years (mean 59.7). Patients were followed up and changes in rhythm, need for pacemaker implantation, and the incidence of CNS (central nervous system) complications were retrospectively studied. RESULTS The follow-up was complete in 103 patients and 99 long-term survivors (99%). The mean follow-up period was 44.6 +/- 1.1 months. In the immediate postoperative period, 73 patients regained sinus rhythm (SR group), 21 patients were in AF (AF group), and six patients underwent pacemaker implantation because of sick sinus syndrome (SSS). During the follow-up period, eight patients died. One- and 5-year survival rates (Kaplan-Meier) after surgery was 95.1 +/- 2.3 and 87.8 +/- 3.4% for the entire group. Preoperative NYHA class was 2.5 +/- 0.7 and medium-term NYHA class was 1.5 +/- 0.5. (P < 0.001) Changes in rhythm for the SR group were followed. Fifty-two patients of the SR group stayed in SR (72%), 16 patients converted back to AF (22%), and four patients had newly-developed SSS (6%) at follow-up period. Probability in SR maintenance for SR group at 1 year was 88.8 +/- 3.7% and at 5 years was 64.8 +/- 7.5%. Five patients experienced the CNS complication during the follow-up period. Two of the AF group and two of the SR group patients developed cerebral/cerebellar infarction. One of the SR group patients experienced small cerebral bleeding. CONCLUSIONS The medium-term results after the modified Cox/Maze III procedure concomitant with other cardiac procedure are good with improved functional status and good survival rate. However, there seems to be gradual but constant attrition in the rate of SR maintenance in SR group.

Successful utilization of the median sternotomy approach in the management of descending necrotizing mediastinitis: Report of a case

We describe herein the case of a patient in whom a median sternotomy was successfully employed for mediastinal drainage in the treatment of descending necrotizing mediastinitis (DNM). Although most reports describe cervical or thoracotomy approaches, our experience strongly suggests that median sternotomy is a satisfactory alternative approach for treatment of this disease.

Electrocardiographic nature of restored sinus rhythm after Cox maze procedure in patients with chronic atrial fibrillation who also had other cardiac surgery.

OBJECTIVE: To characterise heart rate variability and high frequency components of restored sinus rhythm after the maze procedure. The maze procedure for chronic atrial fibrillation may prevent thrombotic events and improve the quality of life. However, the electrocardiographic nature of restored sinus rhythm after the maze procedure has not been fully elucidated. PATIENTS AND METHODS: Between March 1993 and August 1995, 104 consecutive patients undergoing the maze procedure in combination with other cardiac surgery were studied. There were 100 long-term survivors (78 with mitral valve disease, 9 with aortic valve disease, 8 with congenital heart disease, and 5 others). Twenty age-matched patients with mitral valve disease who were in normal sinus rhythm preoperatively were enrolled as a control group. 30 days after surgery, the presence of arrhythmias and the circadian changes of heart rate variability were estimated by ambulatory electrocardiographic monitoring and the filtered P duration was evaluated by signal-averaged electrocardiogram. RESULTS: Restoration of sinus rhythm was observed in 73 of 100 cases. Subjects were classified into three groups according to their postoperative ambulatory electro-cardiographic monitoring findings: patients in group 1 (n = 73) (1a: 58 regular sinus rhythm; 1b: 15 sinus rhythm with frequent premature atrial contractions (> 1000/day); patients in group 2 (n = 21) still had persistent atrial fibrillation; and patients in group 3 (n = 6) required permanent pacemaker implantation because of sick sinus syndrome. The success rate of restoration of sinus rhythm was 88.3% if left atrial diameter was small (< 65 mm). Circadian changes in the low frequency to high frequency power ratio in group 1a were significantly diminished compared with control group (P < 0.01). Furthermore, the filtered P duration in group 1a (150 (20) ms) and group 1b (158 (23) ms) were longer than in the control group (122 (11) ms) (P < 0.01). CONCLUSIONS: The maze procedure may result in a decreased sinus response and non-uniform transmission of impulses in the atrium.

Genetic polymorphism of 5,10-methylenetetrahydrofolate increases risk of myocardial infarction and is correlated to elevated levels of homocysteine in the Japanese general population.

BackgroundHyperhomocysteinemia, an independent and graded risk factor for coronary artery disease, can result from both environmental and hereditary factors. C677T mutation of the 5,10‐methylenetetrahydrofolate reductase (MTHFR) gene [alanine/valine (A/V) polymorphism], one of the key enzymes involved in catalyzing the remethylation of homocysteine, has recently been reported. ObjectiveTo evaluate the incidence of the MTHFR genotypes and their significance in determining the risk for myocardial infarction of Japanese men. MethodThe subjects consisted of 199 healthy men (mean age, 60 years) and 230 male patients with myocardial infarction (mean age, 59 years). The coronary‐artery lesions were evaluated by coronary angiography. The MTHFR genotype was analyzed by polymerase chain reaction and then by digestion with HinfI. Total plasma levels of homocysteine for each MTHFR genotype were compared with those in healthy controls. ResultsThe prevalences of the A and V alleles among the healthy male subjects were 0.652 and 0.348 in the Hardy–Weinberg equilibrium. The total levels of homocysteine in the plasma of the healthy male subjects were 8.6±3.3, 8.9±4.1, and 11.6±5.6 mmol/l, for AA, AV, and VV genotypes, respectively. Individuals with the VV homozygous mutant genotype thus had the highest plasma levels of homocysteine. Logistic analysis revealed that the levels of high‐density lipoprotein cholesterol, hypertension, diabetes mellitus, MTHFR VV genotype, and triglycerides were all independent risk factors for myocardial infarction. The VV genotype was more prevalent among patients with myocardial infarction (mean age, 59 years) than it was among the control subjects (17.0 versus 10.6%, P <0.05). However, there were no differences in the numbers of stenotic coronary arteries among the MTHFR genotypes. ConclusionThe VV genotype of MTHFR increases plasma levels of homocysteine in healthy controls, and this mutation indicates a genetic predisposition toward a greater than normal risk of myocardial infarction for Japanese men.

Transient Cortical Blindness Following Bypass Graft Angiography A Case Report

Transient cortical blindness, an uncommonly recognized complication of cerebral angiog raphy, is an exceedingly rare event after cardiac catheterization and angiography. This report describes a sixty-two-year-old patient who had transient cortical blindness following bypass graft angiography. In this case, the authors showed that cortical blindness was associated with the breakage of the blood-brain barrier (BBB) and an increase in vascular permeability rather than with primary cerebral circulatory insuffi ciency. When the possibility exists that an excess volume of contrast medium may enter the cerebral circulation as in this case, that is, following a coronary artery bypass graft (CABG) using the internal mammary artery (IMA), precautionary measures may be necessary such as changing the type of contrast medium to be used or decreasing the volume injected. When cortical blindness occurs, it is a serious clinical problem whether transient or permanent. Therefore, the circumstances leading to this complication should be understood to determine suitable treatment and management.

Polymorphism of the apolipoprotein E and angiotensin I converting enzyme genes in Japanese patients with myocardial infarction.

ObjectiveTo investigate the genetic contribution for myocardial infarction. MethodsWe investigated common polymorphisms of apolipoprotein E gene and angiotensin converting enzyme (ACE) gene in Japanese population. Subjects were 422 healthy people and 254 patients with myocardial infarction. We evaluated the 287 base pair (bp) insertion (I)/deletion (D) polymorphism in intron 16 of the ACE gene and a polymorphism in the apolipoprotein E gene by using the polymerase chain reaction. ResultsThe ACE genotype prevalences for II, ID, and DD were 36.2, 46.1, and 17.7%, respectively, among the myocardial infarction patients. The prevalence of the D allele of the ACE gene among the myocardial infarction patients (0.593) exceeded that among the healthy controls (0.407). The prevalences of the ϵ2, ϵ3, and ϵ4 alleles of the apolipoprotein E genotype among healthy controls were 0.024, 0.882, and 0.094, and those among survivors of myocardial infarction were 0.024, 0.834, and 0.142, respectively. Myocardial infarction patients had an excessive prevalence of the apolipoprotein E ϵ4 allele (P < 0.05). Multiple regression analysis demonstrated that the independent risk factors for developing myocardial infarction were age, DD genotype of ACE gene, and apolipoprotein E ϵ4 allele. Stenotic coronary vessels in myocardial infarction patients did not differ significantly among the patients with various ACE and apolipoprotein E genotypes in the present study. ConclusionsAmong the Japanese, apolipoprotein E ϵ4 carriers and subjects with ACE DD genotype are at an increased risk of myocardial infarction.

Recovery of atrial function after combined treatment with surgical repair for organic heart disease and maze procedure for atrial fibrillation

The maze procedure, a new surgical treatment for lone atrial fibrillation, was initially described by Cox and associates. 1 Recently, combined treatment for organic heart disease and atrial fibrillation has been reported, hut there have been few studies on atrial activity after combined treatment with surgical repair for organic heart disease and the maze procedure for atrial fibrillation. It is important to know how well atrial function recovers after combined surgical methods. Therefore we investigated the recovery of atrial funetion after the combined surgical treatment of organic heart disease and atrial fibrillation. Methods. Twelve patients who received cardiac operation with a successful maze procedure were enrolled in this study. The patients consisted of four men and eight women, with a mean age of 60 _+ 11 years. Organic heart diseases were mitral stenosis in two patients, mitral regurgitation in eight, and atrial septal defect in two. All patients underwent symptom-limited cardiopulmonary exercise testing with use of an upright bicycle ergometer with measurements of atrial natriuretic peptide (ANP) before and after exercise testing and Doppler echocardiography 1 week before the operation (control phase), 1 month after the operation (early phase), and 3 months after the operation (late phase). Ventilatory threshold was determined in a standard manner by the V-slope method. Peak velocities of the early filling (E) wave, atrial filling (A) wave, and A/E ratio were determined by Doppler echocardiography. The timevelocity integrals of the E (Ea) and A (Aa) waves were then obtained by planimetry of the flow velocity profile. Left atrial active contractile fraction (LAACF) was expressed as the ratio of the atrial component during active atrial contraction (Aa) to the total diastolic time velocity integral (Ea + Aa) and calculated as LAACF = Aa/(Ea + Aa).

Survival and sinus rhythm maintenance after modified Cox/maze procedure and mitral valve operation in patients with chronic atrial fibrillation.

OBJECTIVE Sinus rhythm gained after the Cox/maze procedure concomitant with mitral valve operation has demonstrated long-term attrition during the follow-up, no information exists on whether the type of mitral valve operation--(repair vs. replacement)--affects this sinus rhythm maintenance rate. We retrospectively studied patients undergoing concomitant mitral valve operation and Cox/maze procedure to answer this question. METHODS Between April 1993 and August 1995, 87 consecutive patients--35 men and 52 women (mean age: 59.3 years)--with chronic atrial fibrillation and mitral valve disease underwent the modified Cox/maze procedure and concomitant mitral valve operation, with 56 having mitral valve repair (repair group) and 31 mitral valve replacement (replacement group). Patients were followed up and changes in rhythm studied retrospectively. RESULTS Follow-up for a mean 51.3 +/- 11.6 months was completed in 82 of 83 long-term survivors (99%). Repair group surgery survival was 98.1 +/- 1.9% at 1 year and 94.2 +/- 3.2% at 5 based on the Kaplan-Meier method. Replacement group surgery survival was 85.7 +/- 5.9% at 1 year and 82.9 +/- 6.4% at 5. Probability in sinus rhythm maintenance for the repair group at 1 year was 88.6 +/- 5.4% and at 5 years was 67.6 +/- 9.1%. Probability in sinus rhythm maintenance for the replacement group at 1 year was 95.7 +/- 4.3% and at 5 years was 65.0 +/- 11.1%. CONCLUSIONS Medium-term results after the Cox/maze III procedure concomitant with mitral valve operation are good. The attrition of sinus rhythm maintenance appears similar by the completion of 5-year follow-up.