Spinal complication associated with descending and thoracoabdominal aortic aneurysm surgery is most serious. This report deals with the value of the segmental crossclamp technique and/or reimplantation of intercostal arteries for the prevention of this serious complication. The subjects were 107 patients, 87 with descending thoracic and 21 with thoracoabdominal aortic aneurysm who were operated on from May 1987 to March 1992 at the National Cardiovascular Center in Osaka. The staged segmental crossclamp technique was applied in 24, while the reconstruction of intercostal arteries was undertaken in 25 patients. Thirteen patients received both procedures simultaneously. The surgical and hospital mortality rates were 1.8% and 8.4%, respectively. Spinal complications were encountered in 11 patients (8.3%), paraplegia in 2 (1.8%) and paralysis in 7 (6.5%). The incidence of paraplegia or paralysis did not decrease under the crossclamp technique and/or reimplantation of intercostal arteries, although no spinal complication was observed in the last consecutive 33 cases. It was speculated that although advances in surgical techniques in dealing with these lesions have been obtained, these two procedures did not completely prevent spinal ischemia/complication during surgical intervention.

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Angiogenic therapy using fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) is being developed as a novel therapeutic strategy to obtain restoration of blood flow around the ischemia in cases of ischemic cardiovascular disease. In addition, arterial gene therapy through gene transfer by VEGF genes has now reached the stage of clinical application.
Through in vivo animal experiments to determine the angiogenic effects of FGF and VEGF, we hope to obtain clues concerning the clinical applications of these methods.
Methods-1: Twenty-three adult dogs were divided into 3 groups as follows:
Group A-1: 20μg of bFGF was administered intravenously simultaneously with heparin three times per week in 4 dogs.
Group A-2: 20μg of bFGF was administered intravenously three times a week without heparin in 4 dogs.
Group B: 20μg of bFGF was administered intramuscularly three times per week in 5 dogs.
Group C: Sham operation control group consisting of 10 dogs.
Local ischemia was created in the hind limbs of animals in groups A-1, A-2 and B through ligation of the femoral artery. Selective femoral arteriography was performed immediately after ligation at 1 week and 2 weeks postoperatively. Biopsy was also performed either at 1 week or 2 weeks after ligation.
Results-1:
(1) The percent increase in number of collateral vessels of the ischemic zone, as recognized on arteriography, was greater in the bFGF groups compared to group C.
(2) The increase in collateral vessels peaked at 1 week.
(3) No difference in angiogenic effect was observed in relation to the method of administration.
(4) The combined administration of heparin had no angiogenic effect.
(5) The hemoglobin content of the biopsy specimens was significantly greater in the 3 groups receiving bFGF compared to group C.
Methods-2: The same study was performed using VEGF as detailed in Method-1.
Results-2: As in the first experiment, a significant increase in collateral vessels was seen in the VEGF group compared to the control group.
Both exogenous bFGF and VEGF significantly promote collateral vessel development and appear to be effective novel therapeutic agents for the treatment of ischemic disease.

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The aim of this study was to assess the incidence of myocardial infarction among persistent perfusion defects in dipyridamole-stress thallium scintigraphy by inspecting autopsied hearts and to evaluate whether the regional thallium activity of a scintigraphic defect can predict the presence of infarction. Autopsied hearts were compared with dipyridamole myocardial scintigrams undertaken during life in 27 patients (mean age 85±8 years), The time interval from stress testing until death was 428±351 days. Regional thallium uptake of delayed perfusion defect was calculated on the short axis images. The grade of regional myocardial fibrosis in autopsy specimens was also quantified to correlate with the corresponding regional thallium uptake. In 6 of 15 (40%) regions with persistent defects on the scintigram, myocardial infarction was not found at autopsy. Regional thallium-201 uptake of delayed defects <50% diagnosed infarction with a sensitivity of 82% and a specificity of 80%. A linear correlation (r=-0.67) was observed between percent thallium-201 uptake and the degree of myocardial fibrosis. In conclusion, perfusion defects at 4-hour imaging in dipyridamole-stress testing may overestimate the presence of myocardial infarction and regional thallium-201 activity is helpful in distinguishing between defects with and without infarction.

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To determine whether syncope predisposes to sudden cardiac death, variant angina patients with syncope during cardiac attacks were compared with those without syncope. There were 240 consecutive patients (193 males and 47 females) diagnosed with variant angina pectoris. Thirty patients had a history of syncope during cardiac attacks while the remaining 210 had none. The incidence of cardiac events in the former group was 10.0% (3 of 30) and 10.5% in the latter. There were 3 cases of sudden cardiac death, all in the latter group. Significant clinical variables in the syncope patients included inferior ST-segment elevation and serious arrhythmias. We conclude that there is no relationship between syncope during variant angina and sudden cardiac death.

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Lipid lowering therapies were employed to prevent restenosis following elective percutaneous transluminal coronary angioplasty (PTCA). The effect of probucol was compared to that of Pravastatin in 141 coronary atherosclerosis patients. Probucol (750mg/day) was administered for at least 30 days prior to PTCA (34 patients, group P-1) or less than 14 days prior to PTCA (27 patients, group P-2). Pravastatin (10mg/day) was administered for at least 30 days prior to PTCA (38 patients, group V-1) or less than 14 days prior to PTCA (42 patients, group V-2). In group P-1, the patient restenosis rate was 17.6% and lesion restenosis rate was 14%. These rates were significantly lower than those of group V-1, which were 44.7% and 40.4% respectively (p<0.05). The respective values were 48.1% and 51.8% in group P-2 (p<0.05, vs group P-1) and 35.7% and 34% (p<0.05, vs group P-1) in group V-2. Probucol seems to work, not only by lowering cholesterol but also by its antioxidative properties when administered for a sufficient period prior to PTCA.

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To determine whether transmitral and pulmonary venous flow velocity patterns can be used to evaluate left atrial pressure and volume changes during atrial systole, we performed transesophageal pulsed Doppler echocardiography and right heart catheterization in 85 patients (20 with hypertrophic cardiomyopathy, 20 with dilated cardiomyopathy, 30 with prior myocardial infarction, and 15 with mitral regurgitation), and 35 normal subjects. Pulsed Doppler variables from transmitral and pulmonary venous flow velocities dur-ing atrial systole were compared with mean pulmonary capillary wedge pressure (mean PCWP), pressure rise during atrial systole (PCWP-A), and left atrial volume change during atrial systole (ΔLAV). The mean PCWP correlated significantly with the peak atrial systolic transmitral flow (r=-0.38, p<0.05) and pulmonary venous flow (r=0.40, p<0.05) velocities in all patients. The PCWP-A correlated significantly with the peak atrial systolic transmitral flow (r=-0.39, p<0.05) and pulmonary venous flow (r=0.68, p<0.0001) velocities in all patients. There was a particularly close correlation between the PCWP-A and the peak atrial systolic pulmonary venous flow velocities. The sum of the time-velocity integral of the atrial systolic transmitral and pulmonary venous flow velocities (TAI) correlated closely with the ΔLAV (r=0.70, p<0.0001) in all patients. Thus, the peak atrial systolic pulmonary venous flow velocity corre-lated well with left atrial pressure changes during atrial systole. Furthermore, the sum of the time-velocity integral of the atrial systolic transmitral and pulmonary venous flow velocities correlated well with left atrial volume changes during atrial systole. Therefore, transesophageal echocardiographic measurements of atrial systolic transmitral and pulmonary venous flow velocities arereasonable indicators of left atrial pressure and volume changes during atrial systole.

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To predict the hemodynamic conditions in patients with mitral stenosis (MS), continuous blood pressure responses were monitored noninvasively at the bedside by arterial tonometry during the Valsalva maneuver in 18MS patients aged 54.2±9.1 (40∼77) years (6 men, 12 women). Two indices during the Valsalva maneuver (blood pressure decline value at phase III (BPdec) and subsequent blood pressure overshoot value at phase IV (BPov)) were compared with hemodynamic data obtained by the cardiac catheterization method, and the correlations between the changes in these parameters were examined.
In these 18 patients, BPdec showed a significant negative correlation with the mean diastolic pressure gradient between the left atrium and left ventricle and showed a significant negative correlation with pulmonary capillary wedge pressure (PCWP) (r=-0.62, p<0.01, r=-0.53, p<0.05, respectively). Mitral valve area (MVA) showed a significant positive correlation with BPdec (r=+0.63, p<0.01). Similarly, BPov showed a significant positive correlation with cardiac output (CO), cardiac index (CI) and MVA (r=+0.60, p<0.01, r=+0.64, p<0.01, r=+0.65, p<0.01, respectively).
Thus, continuous monitoring of blood pressure by arterial tonometry during the Valsalva maneuver is useful for predicting the hemodynamic conditions in patients with MS.

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Objectives: To assess the cardioprotective efficiency of an antioxidant regimen (vitamins E, C and N-acetylcysteine) in patients receiving high dose chemo- and/or radiotherapy for malignant disease.
Methods: Prospective, placebo controlled, randomized and double blinded pilot study involving 13 patients receiving chemotherapy and 12 patients receiving radiotherapy.
Results: In patients receiving antioxidants, left ventricular ejection fraction did not change (63±4% to 63±4%). In the placebo group, ejection fraction changed from 67±6% to 61±4% (p=0.03). No patient in the antioxidant group and 6/13 (46%) patients in the placebo group showed a fall of >10% in the left ventricular ejection fraction. In the chemotherapy group, the left ventricular ejection fraction changed from 62% (±2) to 63% (±2) in the patients treated with antioxidants (ns) and from 63% (±5) to 61% (±5) in patients treated with placebo (ns). No patient showed a significant fall in ejec-tion fraction in the antioxidant group, whereas 2/7 (29%) in the placebo group showed a reduction ≥10%. In the radiotherapy group, left ventricular ejection fraction did not change {64% (±6) to 64% (±5)} in patients treated with antioxidants (ns) and changed from 70% (±8) to 60% (±4) in patients treated with placebo (p=0.008). No patient in the antioxidant group, but 4/6 (66%) patients in the placebo group showed a fall of ≥10% in ejection fraction.
Conclusion: The small number of patients in the study precludes a definitive statement. The preliminary results however suggest efficient cardioprotection by this nontoxic and inexpensive antioxidant combination, so larger studies are warranted for confirmation.

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Vasovagal syncope is a common clinical problem, however the hemodynamic mechanism is not clearly understood. The aim of the present study was to investigate the circulatory control mechanism of vasovagal syncope provoked by the head-up tilt test. Thirty two patients with recurrent unexplained syncope were studied using a head-up (60°) tilt test. The electrocardiogram, arterial blood pressure, pulmonary arterial pressure and central venous pressure were monitored continuously, and the cardiac output was measured by the thermodilution method. Twenty patients (62.5%) had positive tilt test responses, of which 12 developed typical vasovagal syncope with marked hypotension and bradycardia; the others developed hypotension without bradycardia. There were five women and seven men with a mean age (±SD) of 53.3±15 years. The effect of head-up tilt resembled that of hypovolemia. The central venous pressure, pulmonary capillary wedge pressure and cardiac output declined with an increase of heart rate and systemic vascular resistance. However the mean blood pressure was maintained. During vasovagal syncope, the heart rate and blood pressure fell precipitously and significantly, the cardiac index was reduced from 2.22±0.43 to 1.51±0.32 liters/min/m² (p value<0.05) and the systemic vascular resistance index decreased from 3, 689±859 to 1, 999±543.9 dynes s cm⁵/m² (p value<0.05). The results of our study showed that both reduction of cardiac output and withdrawal of sympathetic vasoconstriction tone contribute to the development of hypotension in vasovagal syncope.

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To evaluate the significance of the refractory period and conduction time of the AV node for reentrant tachycardias incorporating the AV node, the effective refractory period of the AV node (ERP) and AH interval (AH) during atrial pacing at various cycle lengths were measured in 12 anesthetized dogs after verapamil administration. ERP-AH tended to be constant in each dog at different cycle lengths and increased as the AV node was suppressed. In reentrant tachycardia incorporating the AV node, assuming that the conduction time outside of the AV node is constant, the excitable gap decreases as ERP-AH increases and disappears if ERP-AH is prolonged up to the conduction time outside of the AV node. ERP-AH was calculated as an index of the excitable gap. On the other hand, ERP/AHs were significantly correlated with cycle lengths and tended to be similar at the same cycle length among the different dogs. ERP/AH is considered to be an index of the wavelength which is expressed as the product of refractory period and conduction velocity. However, because ERP was always longer than AH, ERP/AH was not applicable as an index of the wavelength in the AV node. The length through which the wavefront ran during the refractory period of the AV node was also dependent on ERP-AH. In conclusion, prolonging ERP-AH played an important role in suppressing reentrant tachycardias incorporating the AV node.

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To investigate the changes in electrical activity after reoxygenation, guinea pig papillary muscles were reoxygenated with 5mM glucose solution after various durations (30-120min) of substrate-free hypoxia. Action potential duration recovered to the control level on reoxygenation following 30-120min hypoxia. The recovery of developed tension or resting tension was incomplete after reoxygenation following longer periods of hypoxia. There was a high incidence of arrhythmias on reoxygenation after 60min hypoxia, which have been shown to be triggered activities due to delayed afterdepolarizations. In some muscles reoxygenated after prolonged hypoxia (90-120min), there was electrical heterogeneity which was shown by variable action potential durations and configurations. There was also conduction block around the microelectrode site in muscle. It was suggested that the electrical heterogeneity and conduction block could predispose to reentry, and that triggered activities and reentry could be involved in the genesis of arrhythmias on reperfusion.

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Cardiac sources of embolic stroke include various abnormalities of the atrial septum. An atypical detachment of the septum primum was detected in two patients by dynamic three-dimensional echocardiography (DTDE). Between the septum primum and septum secundum a cavity with interatrial communication was detected. Within the cavity a turbulent color Doppler signal and an entry of the contrast agent Echovist^R were detected. One of the patients suffered from repeated cerebrovascular events. This unusual defect of the atrial septum may be a potential source of embolism. Transesophageal echocardiography is considered the most sensitive method for the examination of the atrial septum. However, clear anatomic details could only be shown by DTDE.

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Two case control studies were performed to evaluate whether smoking may affect myocardial function. Cardiomyopathy subjects had a greater pack year smoking history than 52 control subjects with no CAD (p<0.02) and were more likely to have diabetes (p<0.10), but they did not differ from controls with respect to age, alcohol intake, or the presence of hypertension. The risk of cardiomyopathy doubled with an increase of 39 pack years. Smoking history was not related to ejection fraction for subjects with severe coronary artery disease. These results suggest that smoking may be an important risk factor for idiopathic congestive cardiomyopathy.

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While the risk of deep venous thrombosis (DVT) during prolonged flights is well recognized, we present the case of a 54-year-old male who suffered a deep venous thrombosis following defecation. Defecation, through a combination of the Valsalva maneuver and squatting, led to a DVT due to venous stasis, most marked in the left leg. Color-duplex scanning not only proved a convenient dignostic tool but also allowed for monitoring and documentation of popliteal and saphenous vein recanalization. Being non-invasive and complication-free, color-duplex scanning should be considered for any patient in whom DVT is a possibility.

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