Functional significance of transient collaterals during coronary artery spasm

Coronary collateral vessels appear transiently during vasospasm. To examine the functional role of such collaterals in acute myocardial ischemia, regional coronary flow was determined in patients who showed isolated total spasm in the proximal left anterior descending coronary artery associated with (n = 7, group I) and without (n = 9, group II) collaterals, which were donated by the nonspastic right coronary artery during ergonovine provocative test. Aortic pressure and heart rate were not significantly different in the 2 groups before and during spasm. During vasospasm, the levels of pulmonary artery end-diastolic pressure were significantly higher in group II (19 +/- 2 mm Hg, mean +/- standard error) than in group I (15 +/- 1 mm Hg, p less than 0.05). Under these conditions, great cardiac vein flow (GCVF) measured by thermodilution was markedly reduced in group II (from 60 +/- 4 ml/min to 37 +/- 4 ml/min, p less than 0.01), whereas GCVF was slightly reduced in group I (from 56 +/- 4 ml/min to 51 +/- 4 ml/min), indicating that residual GCVF was greater in patients with than in those without collaterals (p less than 0.05). The calculated coronary collateral resistance index during vasospasm was significantly lower in group I (2.06 +/- 0.18 mm Hg min/ml) than in group II (2.91 +/- 0.30 mm Hg min/ml, p less than 0.05). Total left anterior descending coronary artery spasm with collaterals was less frequently associated with ST elevation in the precordial electrocardiogram recorded during spasm.(ABSTRACT TRUNCATED AT 250 WORDS)     

A simple and effective regimen for prevention of radial artery spasm during coronary catheterization

Radial artery spasm occurs frequently during the transradial approach for coronary catheterization. Premedications with nitroglycerin and verapamil have been documented to be effective in preventing radial spasms. Verapamil is relatively contraindicated for some patients with left ventricular dysfunction, hypotension and bradycardia. We would like to know whether nitroglycerin alone is sufficient for the prevention of radial artery spasm. We conducted a randomized controlled trial to compare the spasmolytic effect between heparin alone, heparin plus nitroglycerin and heparin plus nitroglycerin and varapamil during transradial cardiac catheterization. In this study, a total of 406 patients underwent transradial cardiac catheterization and intervention. After successful cannulation and sheath insertion of radial arteries, 133 patients in group A received 3,000 units of heparin, 100 microg of nitroglycerin and 1.25 mg of verapamil via sheath, 135 patients in group B received 3,000 units of heparin and 100 microg of nitroglycerin, and 93 patients in group C received 3,000 units of heparin. Five patients in group A (3.8%), 6 patients in group B (4.4%) and 19 patients in group C (20.4%) showed radial spasms. There is no statistically significant difference between groups A and B (p = 0.804), but there are strong statistically significant differences between groups A and C (p = 0.001) and groups B and C (p = 0.003). Intra-arterial premedication with 100 microg nitroglycerin and 3,000 units of heparin is effective in preventing radial spasms during transradial cardiac catheterization.     

Relief of refractory angina with continuous intravenous infusion of nitroglycerin

Seventy-five patients with chest pain due to prolonged myocardial ischemia (group I, n=45) or acute myocardial infaction (group II, n=30) were treated with continuous intravenous infusion of nitroglycerin. Pain relief was achieved immediately or after titration in 40 of 45 group I patients and 22 of 30 group II patients. Of the 29 group I patients who received narcotic analgesics for pain relief prior to the nitroglycerin infusion, 20 experienced a decrease in narcotics required for pain relief while intravenously receiving nitroglycerin. Twenty-four of 28 group I patients and 14 of 19 group II patients who had angina refractory to multiple doses of sublingual nitroglycerin received relief with intravenous administration of nitroglycerin. This data suggests that intravenous administration of nitroglycerin is useful, adjunctive therapy for chest pain even when refractory to multiple doses of sublingual nitroglycerin.     

桡动脉痉挛分析及药物干预试验

目的通过桡动脉造影法观察桡动脉痉挛(RAS)的相关因素,比较不同配方血管解痉剂对于RAS的效果。方法接受经桡动脉途径介入治疗(TRI)的患者180例,其中男性97例,女性83例。随机分入硝酸甘油组(硝酸甘油200μg),尼卡地平组(尼卡地平200μg),鸡尾酒组(硝酸甘油100μg+尼卡地平100μg),每组60例。在常规桡动脉造影后分别经鞘给予协定药物。给药后1、2 min分别行桡动脉造影。以方差分析法比较3组患者给药前、给药后1、2 min RAS发生率的变化。桡动脉痉挛程度通过计算机定量分析法(QCA)测得,桡动脉狭窄>70%定义为桡动脉痉挛,出现导管因痉挛发生推送、旋转困难以及拔管时阻力大、疼痛等临床表现定义为临床桡动脉痉挛。用Logistic回归分析桡动脉痉挛相关因素。结果 180例患者桡动脉正常参考段内径在基线水平为1.08～3.76 mm,平均为(2.24±0.52)mm。用药前RAS总发生率为10.6%,临床RAS发生率为6.2%。桡动脉直径、桡动脉鞘直径及既往TRI术≥2次是RAS的独立相关因素。硝酸甘油组、尼卡地平组和鸡尾酒组在桡动脉穿刺后RAS的发生率分别为15.0%、8.3%和8.3%,给药后1 min分别降至3.3%、5.0%和1.7%,给药后2 min分别降至1.7%、3.3%和0%。硝甘-尼卡组、尼卡-鸡尾酒组RAS发生率差异有统计学意义,但硝甘-鸡尾酒组桡动脉RAS发生率差异无统计学意义。结论 RAS总发生率为10.6%,其独立相关因素包括桡动脉直径、桡动脉鞘外径及既往TRI术≥2次。硝酸甘油及尼卡地平均具有明显扩张桡动脉的作用,但硝酸甘油及两者联合应用比单用尼卡地平有更大优势。     

Continuous intracoronary nitroglycerin infusion for spasm after angioplasty

A patient with reversible coronary artery spasm superimposed on fixed atherosclerotic coronary disease was treated with percutaneous transluminal angioplasty. The procedure successfully dilated the atherosclerotic lesion. However, 20 minutes later, the patient developed coronary artery spasm at the angioplasty site. Sublingual nitroglycerin, sublingual nifedipine, intravenous nitroglycerin, and repeated boluses of intracoronary nitroglycerin alleviated episodes of spasm, but failed to prevent recurrence. The patient was successfully treated with a continuous intracoronary infusion of nitroglycerin. Patients with coronary artery spasm in addition to fixed obstructive coronary disease may be at higher risk for spasm after percutaneous transluminal angioplasty. Continuous intracoronary infusion of nitroglycerin may be an effective therapy for recurrent coronary artery spasm occurring in the catheterization laboratory.     

Complete arterial coronary artery bypass grafting versus conventional revascularization--early results

BACKGROUND: Complete arterial coronary artery bypass grafting (CABG) offers the potential to improve long-term results. However, an increased perioperative risk has been controversially discussed. New operative techniques (skeletonization of the ITA/ T-grafts/utilization of the radial artery (RA)) may decrease perioperative risk. We compared the outcome after conventional with that after complete arterial CABG. MATERIAL AND METHODS: Three consecutive groups of patients were analyzed. In group I (n = 50), CABG was performed using left ITA and vein grafts. The other two groups received complete arterial CABG with either both ITA's (group II; n = 52) or left ITA and RA (group III; n = 52). RESULTS: A mean of 3.9+/-0.8 (I) versus 4.2+/-0.8 (II) and 3.9+/-0.9 (III) anastomoses were performed per patient (ns). Mean operating time was significantly prolonged in group II (II: 252+/-54; p<0.0001; vs. I: 191+/-36; III: 203+/-33). Mean ischemic time was significantly prolonged in group II and III (II:65+/-20; p<0.0001; III: 68+/-16; p<0.0001; vs. I: 51+/-15). Mean bypass time (I: 83+/-23; II: 95+/-41; III: 91+/-21), the rate of postoperative complications and in-hospital mortality (I: n = 0; II: n = 2; III: n = 0; ns) showed no significant differences. Conclusions: Complete arterial CABG using modern surgical techniques is as safe as the conventional surgical approach using left ITA and vein graft.     

Intracoronary nitroglycerin reversal of life-threatening ergonovine maleate-induced coronary artery spasm

Ergonovine maleate was given to a patient suspected as a case of Prinzmetal's variant angina following demonstration of normal coronary arteries by angiography. Profound shock, heart block, and severe pain accompanied marked spasm of the left coronary artery. Direct infusion of nitroglycerin into the left coronary artery reversed the spasm when sublingual and intraaortic nitroglycerin failed to prevent further hemodynamic and clinical deterioration.     

The effect of pre-procedure sublingual nitroglycerin on radial artery diameter and Allen's test outcome - Relevance to transradial catheterization

BackgroundThe radial artery is increasingly used for cardiac procedures, but is a relatively small vessel that is prone to spasm when instrumented. Intra-arterial nitroglycerine has been shown to reduce radial spasm but first requires arterial access. We investigated the effect of pre-procedure sublingual nitroglycerin (NTG) on the diameter of the radial artery in a large cohort of patients.Methods305 subjects underwent ultrasound measurement of their radial and ulnar arteries in both arms before and after the administration of 800 μg of sublingual NTG. The Allen's test was also performed in the subjects prior to and after NTG.ResultsRadial artery diameter in this Caucasian study group is larger than that reported for other populations. The administration of sublingual NTG significantly increased the size of the right radial artery from 2.88 ± 0.36 mm to 3.36 ± 0.40 mm in men and from 2.23 ± 0.37 up to 2.74 ± 0.36 mm in women. There were also significant increases in left radial, right and left ulnar artery diameters in males and females with NTG. There was no significant effect of NTG on blood pressure. In all patients with an unfavourable Allen's test, retesting following sublingual NTG resulted in transition to a favourable Allen's.ConclusionCaucasian populations have larger calibre radial arteries compared to other geographic areas. Sublingual NTG is effective at dilating the radial artery in both men and women. This may make radial artery puncture and cannulation less challenging and should be considered in all patients in the absence of contraindications. The results of Allen's testing are dynamic and its usefulness for screening prior to transradial access is undetermined.     

Effects of residual coronary artery disease on results of coronary artery bypass grafting

To assess the effects of residual coronary artery disease (non-revascularized coronary vessels) after coronary artery bypass grafting on symptoms and exercise left ventricular function, we categorized 77 patients into 3 groups according to the extent of residual coronary artery disease: group I (n = 17) had no residual coronary artery disease (residual score = 0); group II (n = 30) had light residual coronary artery disease (score of 1 to 9, mean 4.7); and group III (n = 30) had moderate residual coronary artery disease (score greater than or equal to 10, mean 23). Sixty patients were asymptomatic after coronary artery bypass grafting (14 in group I, 24 in group II, and 22 in group III), but the remaining patients had occasional angina pectoris. The resting left ventricular ejection fraction was significantly higher in group I than in the remaining 2 groups (56 +/- 18% in group I, 47 +/- 19% in group II, and 43 +/- 16% in group III, P less than 0.05). The exercise left ventricular ejection fraction was also significantly higher in group I (61 +/- 16% in group I, 51 +/- 18% in group II and 45 +/- 18% in group III, P less than 0.01). The ejection fraction response to exercise was abnormal in 5 patients in group I, 15 patients in group II, and 19 patients in group III. Thus, coronary artery bypass grafting results in symptomatic improvement, even in patients with residual coronary artery disease. The presence of residual coronary artery disease, however, may be a determinant of exercise left ventricular function in these patients.     

Dissociation of coronary vascular tolerance and neurohormonal adjustments during long-term nitroglycerin therapy in patients with stable coronary artery disease

Objectives. We sought to examine whether long-term nitroglycerin treatment causes tolerance in large coronary arteries and whether the loss of vascular effects parallels neurohormonal adjustments.Background. Nitroglycerin therapy is associated with increased plasma renin activity and aldosterone levels and a decrease in hematocrit. It is assumed that nitroglycerin tolerance results in part from these neurohormonal adjustments and intravascular volume expansion.Methods. Three groups were studies: group I (n = 10), no prior nitroglycerin therapy; and group II (n = 10) and group III (n = 8), 24- and 72-h long-term nitroglycerin infusion (0.5 μg/kg body weight per min), respectively. Coronary artery dimensions were assessed using quantitative angiography. Plasma renin activity, plasma aldosterone and vasopressin levels and hematocrit were monitored before and during nitroglycerin infusions.Results. In group I, increasing intravenous concentrations of nitroglycerin caused a dose-dependent increase of the midportion of the left anterior descending coronary artery (baseline diameter 2.13 ± 0.07 mm [mean ± SEM], maximally by 22 ± 2%) and left circumflex coronary artery (baseline diameter 2.08 ± 0.07 mm, maximally by 22 ± 3%). An intracoronary nitroglycerin bolus (0.2 mg) caused no further significant increase in diameter, indicating maximal dilation. In group II (n = 10), the baseline large coronary artery diameter under ongoing nitroglycerin was significantly larger than that in group I (left anterior descending artery 2.61 ± 0.08 mm, left circumflex artery 2.57 ± 0.08 mm). Additional intravenous and intracoronary nitroglycerin challenges did not cause further dilation, indicating maximally dilated vessels. At the same time, plasma renin activity, plasma aldosterone and vasopressin levels were significantly increased, and hematocrit significantly decreased. In group III patients, the baseline diameter of the left anterior descending artery and the left circumflex artery did not differ from that in patients without nitroglycerin pretreatment, indicating a complete loss of nitroglycerin coronary vasodilative effects. These patients showed no significant increase in circulating neurohormonal levels but a significant decrease in hematocrit.Conclusions. Within 24 h of continuous nitroglycerin treatment, the coronary arteries were maximally dilated despite neurohormonal adjustments and signs of intravascular volume expansion. Within 3 days of nitroglycerin infusion, tolerance developed in the absence of neurohormonal activation. The dissociation of neurohormonal adjustments and tolerance in large coronary arteries indicates that after long-term nitroglycerin treatment, true vascular tolerance, perhaps from an intracellular tolerance step, may have developed.     

Effects of subcutaneously infiltrated nitroglycerin on diameter,palpability, ease-of-puncture and pre-cannulation spasm of radial artery during transradial coronary angiography

Background

The success of transradial catheterization depends on meticulous access of radial artery which in turn depends on palpating a good radial pulse.

Objectives

Our objectives were to analyze the effects of subcutaneously infiltrated nitroglycerin on diameter of radial artery, palpability of radial pulse, ease-of-puncture and pre-cannulation spasm of radial artery during transradial coronary angiography.

Methods

Patients undergoing transradial coronary angiography were randomized to Group NL or Group SL. In Group NL, 3 ml of solution containing nitroglycerin and lignocaine was infiltrated subcutaneously at the site intended for puncture of radial artery. Similarly, saline and lignocaine were infiltrated in Group SL. Diameter of radial artery was objectively assessed by ultrasonography. Measurements were performed at baseline and repeated at 1 min after injecting the solutions. The ease-of-puncture was evaluated by the number of punctures and the time needed for successful access of radial artery.

Results

Both groups had 100 patients each. Baseline diameter of radial artery was similar between two groups. The post-injection diameter of radial artery increased by 26.3% in Group NL and 11.4% in Group SL. Nitroglycerin significantly improved the palpability of radial pulse, reduced the number of punctures and shortened the time needed for successful access of radial artery. Pre-cannulation spasm of radial artery occurred in 1% of Group NL and 8% of Group SL.

Conclusions

Subcutaneously infiltrated nitroglycerin leads to significant vasodilation of radial artery. This avoids pre-cannulation spasm of radial artery, enhances palpability of the radial pulse and thus makes the puncture of radial artery easier.     

Feasibility of Nitroglycerin Patch as a Pretreatment for the Distal Radial Approach: Study Protocol for a Randomized Controlled Trial (DRANG Study)

BackgroundThe distal radial approach (DRA) is a novel catheter cannulation technique to access the distal radial artery for coronary angiography (CAG). It is associated with less occurrence of puncture site occlusion than the conventional transradial approach. However, cannulation failure occasionally occurs due to difficulty in puncturing the smaller distal radial artery. Nitroglycerin is expected to improve the rate of successful DRA via its vasodilative and vasospasm-preventive effects.MethodsThe DRA in CAG using transdermal NitroGlycerin patch (DRANG) study is a single-center, double-arm, parallel-assignment, double-blinded, randomized, controlled trial. Eligible patients with angina pectoris who are scheduled to receive CAG via DRA at the National Cerebral and Cardiovascular Center will be enrolled and allocated to the nitroglycerin group (n = 46) or the no-treatment group (n = 46). The nitroglycerin group will receive a transdermal nitroglycerin patch pre-integrated with a covering material that completely conceals the patch on their upper arm on the puncture side. The no-treatment group will receive only the covering material. Applications are performed 2–8 h before puncture while the patient wears an eye mask. Physicians who are blinded to the allocation and have similar experience with DRA puncture will perform DRA using the Seldinger technique with a 22-gauge needle. The primary outcome is the rate of successful palpation-guided distal radial artery cannulation with the first puncture. The secondary outcomes are the rate of successful distal radial artery cannulation, number of punctures, procedure time, use of ultrasound guidance, diameter of the distal radial artery and changes before and after patch application, and occurrence of arterial vasospasm, occlusion, or hypotension.ConclusionsThis study will allow us to determine the impact of a transdermal nitroglycerin patch on the rate of successful DRA and validate its effectiveness as a DRA pretreatment.Trial registrationjRCTs051210128.     

Complete arterial revascularisation in patients older than 70 years.

BACKGROUND: Coronary artery bypass grafting (CABG) using left internal thoracic artery and vein grafts is standard in patients of advanced age. A number of these patients, however, present without suitable vein grafting material and thus require the use of arterial conduits. In order to investigate the safety and efficacy of complete arterial revascularisation, we have compared the perioperative results of patients older than 70 years with conventional CABG and complete arterial revascularisation. PATIENTS AND METHODS: Group I (n = 172) with conventional CABG in 1999 was compared with 152 patients (group II) with complete arterial CABG between 1996 and July 2000. There were no significant differences regarding age, gender, left ventricular ejection fraction or incidence of three-vessel disease or left main stenosis. The proportion of reoperations was significantly higher in group II (16 %) vs. group I (4 %). RESULTS: A mean of 3.7 +/- 0.7 anastomoses (I) versus 4.0 +/- 0.9 (II) were performed per patient (p = n. s.). Mean operating time (I: 210 +/- 46 min; II: 194 +/- 46 min) and bypass time (I: 87 +/- 25 min; II: 78 +/- 29 min) were significantly lower in group II. Ischemic time (I: 46 +/- 22 min; II: 49 +/- 21 min) was not significantly different. The incidence of sternal dehiscence was 2.9 % (I: n = 5) vs. 1.3 % (II: n = 2). Hospital mortality was 4.6 % in group I vs. 3.9 % (II). CONCLUSION: Complete arterial revascularisation is a safe option in patients aged over 70. It remains to be shown whether it may also have advantage in the long term.     

Possible role of high susceptibility of high-density lipoprotein to lipid peroxidative modification and oxidized high-density lipoprotein in genesis of coronary artery spasm

Recent study demonstrated high susceptibility of plasma LDL to lipid peroxidative modification in patients with variant angina. Oxidized stress state, especially oxidized LDL, may induce coronary artery spasm by its impairing effect of endothelium-dependent arterial relaxation, but precise mechanisms remain unclear. Study subjects included 93 patients who underwent coronary angiographic examination: 12 patients with coronary artery spasm provoked by ergonovine without organic stenosis (group I), 11 patients who did not demonstrate coronary artery spasm or organic stenosis (group II) and 70 patients with organic coronary artery stenosis (group III). Levels of plasma HDL-cholesterol and apoA-I in group I were similar to those in III but were significantly lower than those in II, although the other plasma lipid parameters were not different among the three groups. The levels of TBARS in plasma and HDL were significantly higher in group I than in II or III (2.94±1.56 vs. 1.91±0.35 or 2.23±0.89 nmol MDA/ml and 1.23±1.00 vs. 0.54±0.37 or 0.70±0.63 nmol MDA/mg protein; P<0.05), although the levels of TBARS in LDL were not significantly different. In the monitoring curve of diene production during copper-induced lipid peroxidation of HDL, its propagation slope was steeper and levels of maximum diene absorbance was higher in group I as compared with that in II or III, but not found in those of LDL. These results suggested that high susceptibility of HDL to lipid peroxidative modification in group I may contribute to the genesis of coronary artery spasm, and oxidized HDL rather than oxidized LDL is more likely to be related to coronary artery spasm.     

Dose and time dependence of hemodynamic tolerance development during intravenous nitrate therapy in acute myocardial infarct

Intravenous nitroglycerin therapy during acute myocardial infarction has beneficial effects on infarct size, infarct complications, and mortality. Numerous dosage formulas for the continuous administration of nitrates are currently used, although several studies have demonstrated the rapid development of tolerance during long-term treatment in patients with ischemic heart disease. The dose and dosage of a continuous nitrate application in the clinical setting of acute myocardial infarction has thus yet to be resolved. This study investigated the hemodynamic effects of a 60-h, low- (33 micrograms/min) vs high- (133 micrograms/min) dose intravenous nitroglycerin (NTG) infusion in 16 patients with uncomplicated acute myocardial infarction. In group I (33 micrograms/min NTG; n = 8) the initial nitrate effect on the pulmonary capillary pressure (PCP-control: 14 +/- 1.5; 4 h: 7 +/- 0.9; 60 h: 7 +/- 0.8; mean +/- SEM; all values in mm Hg) and mean pulmonary artery pressure (PAPM-control: 23 +/- 2.3; 4 h: 15 +/- 1.3; 60 h: 14 +/- 1.3) remained unchanged for 60 h. In group II (133 micrograms/min NTG; n = 8) an almost complete loss of the initial effect on PCP (control: 15 +/- 1.6; 4 h: 5 +/- 1.4; 60 h: 12 +/- 1.3) and PAPM (control: 25 +/- 2.0; 4 h: 14 +/- 1.8; 60 h: 20 +/- 1.3) was observed. In contrast to high-dose application the low-dose NTG-infusion induced comparable acute hemodynamic effects that were not attenuated by tolerance development.     

Vasospasms of the radial artery after the transradial approach for coronary angiography and angioplasty

We examined vasospasms of the radial artery after a transradial approach was used for coronary angiography or angioplasty. In forty-eight patients (39 males and 9 females), arteriography of the radial artery was initially performed just after the transradial approach was used for coronary angiography and/or angioplasty. Then, five months later, a second arteriography of the radial artery was obtained after a transbrachial approach was used for coronary angiography. First and second arteriographies were compared to evaluate vaso-spasms of the radial artery. In the present study, more than 75% stenosis in the radial artery, 25-75% stenosis, and less than 25% stenosis were tentatively defined as severe spasms, moderate spasms, and mild spasms, respectively. In arteriographic studies on the radial artery, twenty-four patients (50%) had severe radial artery spasms, eleven patients (23%) had moderate spasms, and thirteen patients (27%) had mild spasms. The diameters of both the proximal and distal radial arteries in the severe spasm group were significantly smaller than those in the mild and moderate spasm groups (proximal site: severe group 2.39 +/- 0.70 mm versus mild group 2.98 +/- 0.46 mm, P < 0.05, and moderate group 2.96 +/- 0.77 mm, P < 0.05, distal site: severe group 2.26 +/- 0.60 mm versus mild group 2.73 +/- 0.47 mm, P < 0.05, and moderate group 2.86 +/- 0.71 mm, P < 0.05). We concluded that vasospasms of the radial artery occurred in most patients after the transradial approach. Furthermore, severe radial spasms were strongly correlated with the size of the diameter of the artery.     

Effect of nitroglycerin on left ventricular function in patients with ischemic heart disease

To evaluate the effects of nitroglycerin on left ventricular function in 27 patients with ischemic heart disease, ejection fraction (EF) was measured every 1 to 5 min by a nuclear stethoscope after sublingual administration of nitroglycerin (0.3 mg). There was a good correlation between EF determined by the nuclear stethoscope and EF by left ventriculography (r = 0.80, p less than 0.001). EF showed a rise after sublingual nitroglycerin, which was most marked at 4 to 7 min and returned to the control level in 20 to 25 min. There were no significant differences in the maximum percent increase in EF among patients with 0, 1, 2 and 3 vessel disease. The maximum percent increases in EF were 34.0 +/- 10.0% in the normal contraction group, 24.0 +/- 8.5% in the hypokinesis group (p less than 0.05 vs the normal contraction group) and 15.2 +/- 8.5% in the akinesis group (p less than 0.01 vs the normal contraction group, p less than 0.05 vs the hypokinesis group). There was a weak correlation between the maximum percent increase in EF and the changes in heart rate (r = 0.49, p less than 0.05) and there was an inverse correlation between the maximum percent increase in EF and the changes in systolic blood pressure (r = -0.65, p less than 0.01). It was shown that the improvement in EF by sublingual nitroglycerin was greatest in the normal contraction group, somewhat less in the hypokinesis group and least in the akinesis group. The nuclear stethoscope is useful in monitoring changes in left ventricular function during intervention.     

Effect of chronic pressure and volume stress on the function of the right ventricle

Biplane right ventricular angiography was performed in 36 patients with chronic pressure overload of the right ventricle; 12 patients additionally had tricuspid insufficiency (TI). There were 4 subgroups: patients with systolic pulmonary artery pressure less than or equal to 40 mm Hg without (group I, n = 10) and with TI (group II, n = 6), as well as patients with systolic pulmonary artery pressure greater than 40 mm Hg without (group III, n = 14) and with TI (group IV, n = 6). Compared with the normal volumes of groups I and III, a significant increase in end-diastolic right ventricular volumes (p less than 0.01) was found in groups II and IV with 112.2 +/- 22.3 ml/m2 and 116.3 +/- 27.4 ml/m2, respectively. In both groups II and IV end-systolic volumes were also significantly increased, with 51.0 +/- 10.3 ml/m2 in group II and 49.7 +/- 11.3 ml/m2 in group IV. Right ventricular ejection fraction was 53.8 +/- 11.9% in group II, 57.3 +/- 8.5% in group III and 57.8 +/- 7.3% in group IV. There was no significant difference between the ejection fraction of these groups in comparison to the normal ejection fraction of group I with 63.4 +/- 10.9%. The results suggest that the right ventricle can compensate for moderate chronic pressure and volume overload using the Frank-Starling mechanism. Overall right ventricular dysfunction is not determined primarily by the loading conditions alone. Local myocardial and septal involvement is suspected to be an important determinant of right ventricular function.     

Experimental study on myocardial salvage by coronary thrombolysis and mechanical recanalization

Salvage of the ischemic myocardium by coronary thrombolysis and mechanical recanalization (simulated angioplasty) was studied in a canine experimental model of acute myocardial infarction induced by coronary occlusive thrombus at the left anterior descending coronary artery. Forty-four open-chest dogs divided into three groups were studied. Group I (n = 15, control group) was observed for 6 hours following the onset of infarct. In group II (n = 14, thrombolysis group), thrombolysis was obtained by intravenous administration of urokinase 2 hours after the onset of infarct. In group III (n = 15, mechanical recanalization group), simulated angioplasty was performed 2 hours after infarct. Coronary reperfusion was continued for 4 hours in groups II and III. The areas of left ventricular risk and infarct were measured by double staining methods with Evans blue dye and triphenyl tetrazolium hydrochloride. There were no significant differences in control blood flow and risk area in the three groups. Myocardial infarct area/risk area was 65 +/- 3% in group I, 45 +/- 1% in group II, and 35 +/- 2% in group III (group I vs II, p less than 0.001; group II vs III, p less than 0.001). Restored coronary blood flow in the left anterior descending artery was 8 +/- 1 ml/min in group II and 14 +/- 1 ml/min in group III (p less than 0.001). The data suggest that coronary mechanical recanalization is more effective than thrombolysis in salvaging the ischemic myocardium in the early phase of myocardial infarction, most probably because coronary blood flow is better restored by mechanical recanalization.     

Administration of the Rho-kinase inhibitor, fasudil, following nitroglycerin additionally dilates the site of coronary spasm in patients with vasospastic angina

BACKGROUND: The Rho/Rho-kinase signaling pathway is known to be involved in the pathogenesis of coronary artery spasm. Previous studies reported the efficacy of the Rho-kinase inhibitor, fasudil, in the prevention and relief of coronary spasm. The usefulness of fasudil in combination with conventional vasodilating agents, however, has not been fully examined in patients with vasospastic angina. METHODS AND RESULTS: A total of 26 patients (mean age, 61+/-11 years) with documented vasospasm in the left anterior descending coronary artery were examined by the acetylcholine stress test. Coronary diameter at the spasm site was measured at baseline and after the administration of vasodilator agents in the following order: intracoronary nitroglycerin (NTG) (300 microg), intravenous fasudil (30 mg, n=15, fasudil group) or saline (n=11, saline group), and again NTG during coronary angiography. The increase in diameter observed following the first NTG administration was found to be similar in the fasudil and saline groups (38.3+/-23.5% and 42.3+/-17.1%, respectively). The additional change in diameter on fasudil treatment (16.9+/-11.2% increase over the diameter after the first NTG administration) was significantly larger than that with saline (-2.8+/-7.6%, P<0.001). The second administration of NTG did not affect the diameter of the spasm site in either group. CONCLUSIONS: Fasudil further dilated the site of coronary spasm, which had already been treated with NTG in patients with vasospastic angina. These findings support and extend the previous results that showed the feasibility of employing fasudil as a novel therapeutic approach for coronary spasm.