Shinichiro Nishiyama

Hypertrophic nonobstructive cardiomyopathy with giant negative T waves (apical hypertrophy): ventriculographic and echocardiographic features in 30 patients.

Abstract In 30 of 1,002 consecutive patients who had left heart catheterization and cineangiography for evaluation of either ischemic heart disease or cardiomyopathy the electrocardiogram showed giant negative T waves (greater than 10 mm) associated with high QRS voltage (R wave greater than 26 mm in lead V 5 or the sum of the S wave in lead V 1 and the R wave in lead V 5 35 mm or more) in the precordial leads despite absence of hypertension or significant coronary artery disease. In all 30 patients a characteristic spade-like configuration (concentric apical hypertrophy) was observed in the right anterior oblique ventriculogram at end-diastole as well as in the long axis two dimensional echocardiogram. The average apical thickness in these patients (24.8 ± 6.6 mm) was significantly greater than that in normal subjects (9.4 ± 3.1 mm) ( P P P P P It is concluded that these 30 patients have nonobstructive hypertrophic cardiomyopathy with marked concentric hypertrophy in the apex (apical hypertrophic type) and with a different septal shape and contraction pattern from those seen in the obstructive type. This type of hypertrophy appears to be a fairly common type of hypertrophic cardiomyopathy in Japan.

Effectiveness of an antioxidant in preventing Restenosis after percutaneous transluminal coronary angioplasty : The Probucol Angioplasty Restenosis Trial

OBJECTIVES The Probucol Angioplasty Restenosis Trial was a prospective, randomized, controlled study that investigated the effectiveness of probucol therapy in reducing the rate of restenosis after percutaneous transluminal coronary angioplasty (PTCA). BACKGROUND Antioxidants have an inhibitory effect on smooth muscle cell growth in experiments in vitro and in vivo, which suggests a possible pharmacologic effect on restenosis after PTCA. METHODS One hundred one patients were randomly assigned to receive 1,000 mg/day of probucol or control (no lipid-lowering) therapy 4 weeks before PTCA. After 4 weeks of premedication, both groups underwent PTCA. Probucol was continued until follow-up angiography 24 weeks after PTCA. Angiographic results were analyzed at a core laboratory by quantitative coronary angiography. RESULTS Dilation was successful in 46 of 50 patients in the probucol group and 45 of 51 in the control group. At follow-up angiography 24 weeks after angioplasty, angiographic restenosis occurred in 9 (23%) of 40 patients in the probucol group and 22 (58%) of 38 in the control group (p = 0.001). Minimal lumen diameter was 1.49 +/- 0.75 mm (mean +/- SD) in the probucol group and 1.13 +/- 0.65 mm in the control group (p = 0.02). Percent diameter stenosis at follow-up angiography in the probucol group was significantly lower than that in the control group (43.9% vs. 56.4%, p = 0.009). The late loss was 0.37 +/- 0.69 mm in the probucol group and 0.60 +/- 0.62 mm in the control group (p = 0.13). The loss/gain ratio was 0.32 +/- 0.74 in the probucol group and 0.56 +/- 0.81 in the control group (p = 0.059). Net gain was greater in the probucol group than in the control group (0.77 +/- 0.70 vs. 0.48 +/- 0.59 mm, p = 0.053). CONCLUSIONS Probucol administered beginning 4 weeks before PTCA appears to reduce restenosis rates.

Primary coronary artery dissection observed at coronary angiography.

Abstract Primary coronary artery dissection has rarely been reported since Prettys first description in 1931.l Earlier cases, which were diagnosed incidentally at autopsy, yielded a clinical picture of catastrophic acute coronary artery disease, revealed either by sudden death (62%) or acute myocardial ischemia (38%). 2 Recently, however, the diagnosis has been made on clinical grounds. Among the 15 previous case reports of primary coronary artery dissection documented by coronary arteriogram (Table I), the diagnosis was made during coronary angiogram conducted for initial examination of acute myocardial infarction in 13 and during coronary angiogram performed under a diagnosis of angina pectoris in 2 patients.

Effect of probucol on repeat revascularization rate after percutaneous transluminal coronary angioplasty (from the Probucol Angioplasty Restenosis Trial [PART])

To address the issue of whether probucol reduces clinical events after percutaneous transluminal coronary angioplasty (PTCA), we surveyed clinical status at 1 year after PTCA of 101 patients who had entered the Probucol Restenosis Angioplasty Trial. Repeat angioplasty at index lesions were required in 5 patients in the probucol group and in 12 in the control group, suggesting that probucol administered beginning 4 weeks before PTCA reduces repeat revascularization rates for 1 year.

Mechanical efficiency in hypertrophic cardiomyopathy assessed by positron emission tomography with carbon 11 acetate

This study was performed to assess the relation between the regional work and oxidative metabolism in hypertrophic cardiomyopathy (HCM). By using carbon 11 acetate as a tracer of myocardial blood flow (%A(0)) and oxygen consumption (k value), 12 patients with HCM with asymmetric septal hypertrophy and 10 normal subjects were studied. Regional work rate (RWR) of the left ventricle was estimated by wall stress and wall thickness. %A(0) in hypertrophied septum was similar to that in nonhypertrophied free wall (92.6% +/- 2.8% vs 93.5% +/- 3.8%; p = not significant). However, oxygen consumption was significantly lower in hypertrophied septum than in nonhypertrophied free wall (0.043 +/- 0.011 vs 0.057 +/- 0.013 min(-1); p < 0.001). The k value in nonhypertrophied free wall was similar to the value observed in normal subjects (0.062 +/- 0.013). Average values for RWR in hypertrophied septum, nonhypertrophied free wall, and normal subjects were 0.26 +/- 0.07,0.62 +/- 0.02,and 1.98 +/- 0.15 J/cm3/ min, respectively. Furthermore, the analysis of covariance, in which the effect of RWR was removed as a covariate, revealed that the overall RWR-corrected k value was much larger in patients with HCM (0.109 vs 0.062, p < 0.0001) than expected from the decreased regional myocardial work, suggesting that there was a diffused inefficiency in oxygen consumption. We concluded, therefore, that the relative value of oxidative metabolism in patients with HCM is significantly higher than that of the normal subjects, suggesting the presence of reduced mechanical efficiency.

Intravascular imaging of serial changes of disease in saphenous vein grafts after coronary artery bypass grafting

To clarify the structural changes of saphenous vein grafts after coronary artery bypass grafting, intravascular ultrasound and angioscopic images were obtained from 23 grafts in vivo and 5 grafts and 3 new veins in vitro; the images were compared with histologic findings. Intravascular ultrasound demonstrated a single-layered appearance at new veins and all of the angiographically normal grafts within 6 months after surgery. A triple-layered appearance that might be related to the remarkably proliferative and degenerated intima was revealed histologically at 73.3% of the normal sites of grafts between 5 and 10 years after operation. In 83.3% of the stenoses at several years after operation, angioscopy showed yellow atheromatous plaques, often with a friable surface; a heterogeneous, lucent echo pattern was revealed on intravascular ultrasound. Thus intravascular ultrasound and angioscopy may be used to identify the morphologic changes of graft at different points after implantation more precisely than conventional angiography.

Prediction of the severity of coronary artery disease by measurement of lipoprotein (a)

BackgroundA number of clinical studies have shown that high serum lipoprotein (a) [Lp(a)] levels are associated with coronary artery disease (CAD). It is, however, unclear whether increased serum concentration of Lp(a) alone is a significant risk factor for CAD. MethodsWe studied 120 consecutive patients who underwent selective coronary angiography: 34 with old myocardial infarction, 47 with angina pectoris, and 39 without ischemic heart disease. ResultsSerum Lp(a) concentrations measured by an enzyme immunoassay method were significantly higher in both the myocardial infarction (mean 23.5 mg/dL, P<0.01) and angina pectoris (22.6 mg/dL, P<0.05) groups than in the no ischemic heart disease group (14.1 mg/dL). On multiple regression analysis with Friesingers severity score (F score) as the criterion variable, the factors that were independently related to F score were Lp(a) (standard regression coefficient [p] = 0.326, P< 0.01), high-density lipoprotein cholesterol (-0.251, P<0.01), and low-density lipoprotein cholesterol (0.225, P<0.01); other coronary risk factors were not related to the score. Serum Lp(a) levels rose as the number of affected arteries (≥75% stenosis) increased (13.3, 21.7, 21.8, and 30.1 mg/dL for zero, one, two, and three affected vessels, respectively). Very similar results were obtained in 78 selected subjects with normal serum cholesterol (<220 mg/dL). ConclusionsWe conclude that Lp(a) is an independent risk factor for CAD and further predicts its severity.

Coronary artery spasm during coronary artery bypass surgery: its diagnosis, treatment and prevention

Between 1982 and 1983, we experienced four cases of hemodynamic collapse accompanied by an ST-segment depression in the ECG lead II, shortly after the cessation of cardiopulmonary bypass. The bypass graft flows monitored in these patients during the hemodynamic collapse episodes were remarkably low. In three cases, nitroglycerin (0.5–1 mg) was injected directly into the vein graft, which increased the graft flow suddenly, returned the ST-segment to the baseline, and improved the circulatory condition. Since 1984, however, diltiazem has been used in the cardioplegic solution and postoperative drip infusion. Due to the introduction of this drug, coronary artery spasm has not been seen in any of our patients since. These findings show that the monitoring of ST-segment changes and bypass graft flows are useful in the early diagnosis of coronary artery spasm after myocardial revascularization. Direct infusion of nitroglycerin into the vein graft is effective for the treatment of spasm, while diltiazem is useful in the prevention of coronary artery spasm incidental to myocardial revascularization.