Analysis of Heart Rate Variability in a Patient with Takotsubo Cardiomyopathy Syndrome on the Actual Onset Day.

A healthy 73-year-old woman unpredictably developed Takotsubo cardiomyopathy syndrome (TTS) during Holter-electrocardiogram (ECG) recording. Thus, the complete chronological ECG data on the actual onset day of TTS were obtained. Many heart rate variability (HRV) parameters, including the low-frequency components (LF) and the high-frequency components (HF), on the actual onset day and in the healing phase were calculated. The interesting facts on the actual onset day were that the suppression of both LF and HF appeared earlier than the changes of the ECG waveform; and the LF/HF ratio remained within the normal range, although both LF and HF were markedly suppressed. The abnormality on the actual onset day was clear compared with the healing phase. It is noteworthy to obtain the chronological ECG data on the actual onset day of TTS in a healthy patient. The present data are unique in terms of being analyzed on the actual onset day. Although the HRV parameters, including LF and HF, were obviously abnormal, there is some skepticism about using HRV parameters as indices of cardiac autonomic activity. In the present case, it was concluded that the abnormality of cardiac autonomic activity contributed to the onset of TTS. These data are unlikely to ever be replicated, and we hope that this report helps elucidate the TTS mechanism.

Relation of coronary plaque composition determined by 64-slice multidetector computed tomography in patients with suspected coronary heart disease.

Sixty-four-slice multidetector row computed tomography is a noninvasive method of assessing coronary artery stenosis and plaque composition. The aim of this study was to clarify the relation between plaque composition and coronary heart disease. Three hundred sixty consecutive patients and 1,085 plaques were evaluated using 64-slice multidetector row computed tomography. On axial or cross-sectional multiplanar reconstruction images, 3 regions of interest were randomly selected within each plaque. Soft plaques and calcified plaques were defined as having computed tomographic densities <50 and >130 Hounsfield units, respectively. The association between coronary risk factors and plaque composition was analyzed. The number of plaques and the mean computed tomographic density of plaques were significantly higher in men than in women (p = 0.002 and p = 0.04, respectively). Coronary plaques were more frequent in patients with stroke, diabetes, hypertension, and dyslipidemia than in patients without these conditions (all p values <0.001). Calcified plaques were more frequent in patients with hypertension (p = 0.02), and patients with calcified plaques also had significantly lower low-density lipoprotein cholesterol levels (p <0.001). Soft plaques were more frequent in patients with dyslipidemia (p <0.001). Patients with soft plaques had significantly higher low-density lipoprotein cholesterol levels (p = 0.02) and lower high-density lipoprotein cholesterol levels (p <0.001) than those without soft plaques. In conclusion, 64-slice multidetector row computed tomography is a useful noninvasive method for quantifying coronary plaques.

Heart rate recovery after exercise is a predictor of silent myocardial ischemia in patients with type 2 diabetes.

OBJECTIVE: Slow heart rate recovery (HRR) predicts all-cause mortality. This study investigated the relationship between silent myocardial ischemia (SMI) and HRR in type 2 diabetes. RESEARCH DESIGN AND METHODS: The study enrolled 87 consecutive patients with type 2 diabetes and no chest symptoms. They underwent treadmill exercise testing and single-photon emission computed tomography imaging with thallium scintigraphy. Patients with abnormal myocardial perfusion images also underwent coronary angiography. RESULTS: SMI was diagnosed in 41 patients (47%). The SMI group showed slower HRR than the non-SMI group (18 ± 6 vs. 30 ± 12 bpm; P < 0.0001). HRR was significantly associated with SMI (odds ratio 0.83 [95% CI 0.75-0.92]; P = 0.0006), even after adjustment for maximal exercise workload, resting heart rate, maximum heart rate, rate pressure product, HbA(1c), use of sulfonamides, and a history of cardiovascular disease. CONCLUSIONS: HRR can predict SMI in patients with type 2 diabetes.

Stent fracture in the left brachiocephalic vein.

A 68-year-old male hemodialysis patient presented with severe congestion in his left arm. Left arm venography showed a completely occluded left brachiocephalic vein. We chose a self-expandable stent for treating this vein. However, restenosis occurred once at 8 months and again after six additional months. The cause of the restenosis was considered to be a stent fracture. On the first restenosis, we performed redilation with a balloon; on the second restenosis, we chose stent-in-stent with a balloon-expandable stent. At least 9 months after the stent-in-stent procedure, there has been no edema in his left arm. Therefore, stent-in-stent is one of the useful strategies for stent fracture in central venous obstruction.

Impact of statin therapy on coronary intervention for non-ST elevation acute coronary syndrome with decreased low-density lipoprotein cholesterol.

OBJECTIVES: The benefits of treating patients with acute coronary syndrome (ACS) with statins are well established. This study investigated the effects of statins on patients who presented with low levels of low-density lipoprotein (LDL) cholesterol, were diagnosed with non-ST elevation ACS, and subsequently underwent percutaneous coronary interventions (PCI). METHODS: From 2000 to 2003, 87 patients(mean age 68 +/- 10 years, 69 males, 18 females) underwent PCI because of non-ST elevation ACS, and had low LDL cholesterol on presentation. These patients were divided into two groups: those who had been taking statins (S-group, n = 46), and those not taking statins, or controls (C-group, n = 41). Only patients whose LDL cholesterol was < 100 mg/dl at admission (average: 82 +/- 12 mg/dl) were included in the study. Troponin-T (TnT), creatine kinase (CK), CK-MB, and high-sense C reactive protein (hs-CRP) were measured before and 6 hr after PCI. The two groups were evaluated at 6 months clinical follow-up. RESULTS: There was no difference in these markers before PCI in both groups. TnT and CK-MB in the S-group at 6 hr post-PCI were significantly decreased compared to those of the C-group (0.45 +/- 1.34 vs 1.40 +/- 2.37 ng/ml, respectively, for TnT, p = 0.04; 17.2 +/- 45.5 vs 81.3 +/- 157.2 IU/l, respectively, for CK-MB, p = 0.02). Major adverse cardiac events (MACE) defined as death, myocardial infarction, congestive heart failure and target lesion revascularization were evaluated after 6 months. There was no difference in MACE between the two groups. CONCLUSIONS: Statin treatment before PCI in patients with non-ST elevation ACS demonstrated beneficial effects such as less myocardial damage, even though both groups presented with low LDL cholesterol levels. However, no significant effect on MACE was seen at 6 months after PCI.

Cibenzoline attenuates coronary systolic reversal flow in a patient with hypertrophic obstructive cardiomyopathy: a case report.

Effects of cibenzoline on coronary hemodynamics, especially systolic reversal flow, were assessed in a 53-year-old man with hypertrophic obstructive cardiomyopathy by coronary flow study using a Doppler guidewire. Intravenous administration of cibenzoline resulted in decreases in the pressure gradient (60 to 0mmHg) and systolic left ventricular pressure (162 to 126 mmHg), and an increase in systolic arterial pressure (102 to 132mmHg). Furthermore, the systolic reversal flow observed at baseline was markedly diminished following administration of cibenzoline. Therefore, we speculate that cibenzoline reduces ventricular wall stress by diminishing the left ventricular obstruction that occurs with compression of the intramyocardial arteries. Cibenzoline-induced attenuation of coronary systolic reversal flow may be associated with the effectiveness of cibenzoline for diminishing the left ventricular obstruction.

Ultrasound attenuation behind coronary atheroma without calcification: mechanism revealed by autopsy.

When performing intravascular ultrasound studies, the backward echo image can show marked attenuation, although there are no calcified deposits and it may be impossible to detect the intraplaque architecture. The pathology underlying this phenomenon was investigated in autopsy specimens. We hypothesize that the mechanism responsible for the attenuation involves micro-calcification and lipid in unstable plaques causing ultrasonic wave reflection and dispersion.

An example that presented giant aneurysm of the angina pectoris after percutaneous coronary intervention.

We present the case of a 70-year-old woman who was admitted to our hospital with heart failure due to a giant left ventricular aneurysm involving the apex and severe mitral regurgitation. Three months before the hospitalization, percutaneous coronary intervention was performed for severe stenosis of the left main trunk. During the procedure, there were no abnormalities of distal coronary flow due to problems like embolization, and repeat coronary angiography, performed after stabilization of heart failure, showed no new significant stenosis. We diagnosed her condition as a subepicardial aneurysm by pathological examination of the resected specimen.

Fate of unprotected side branches as related to embolic complications during stent implantation for acute coronary syndromes using a distal protection procedure.

Coronary lesion stenting with aspiration and distal balloon occlusion is more often associated with embolic occlusion of interposed side branches when the branch arises at an angle of

Insulin resistance in nondiabetic patients is associated with expansive remodeling in coronary arterial lesions.

OBJECTIVE: Insulin resistance has been implicated as an important initiating factor in coronary atherosclerosis. However, associations between insulin resistance and specific morphologic features of atherosclerotic coronary arteries remain unclear. We ultrasonographically evaluated the morphologic features of atherosclerotic coronary arteries in nondiabetic patients with insulin resistance. METHODS: Before intervention, 90 patients with 105 culprit lesions underwent intravascular ultrasound examination through which vessel area, lumen area and plaque area were evaluated. Expansive remodeling (lesion vessel area more than 5% greater than at the proximal reference segment) and constrictive remodeling (lesion vessel area more than 5% less than at the distal reference segment) were also evaluated. Insulin resistance was determined by homeostasis model assessment and defined as values above the 75th percentile (that is, 1.71). RESULTS: Insulin-resistant patients numbered 23, while nonresistant patients numbered 67. Culprit lesions in the insulin-resistant group showed larger vessel area (18.16 +/- 6.94 compared with 13.64 +/- 4.28 mm, P = 0.0001) and plaque area (16.64 +/- 6.78 compared with 12.05 +/- 4.12 mm, P = 0.0001) and more frequently showed expansive remodeling (56% compared with 14%, P < 0.0001) and calcific plaque (33% compared with 12%, P = 0.01). Multivariable logistic regression analysis identified only insulin resistance (odds ratio, 4.9, P = 0.008) as an independent predictor of expansive remodeling. CONCLUSIONS: Insulin resistance independently predicted expansive remodeling, underscoring the importance of insulin resistance in coronary atheroscrelosis.

Chronic stent recoil plays an important role in restenosis of the right coronary ostium.

OBJECTIVE: The efficacy of coronary stenting of aorto-ostial atherosclerotic lesions is still unclear. We investigated the frequency and mechanism of stent restenosis at this particular lesion. METHODS: Fifty-five consecutive patients with 64 native aorto-ostial lesions in the right coronary artery (RCA, n = 38) and the left main trunk (LM, n = 26) were treated by conventional stenting. Determinants of angiographic restenosis were established. The mechanism of stent restenosis was evaluated using post-stenting and follow-up intravascular ultrasound (IVUS) findings. RESULTS: Restenosis was more frequent in the RCA than in the LM (50% compared with 19%, P < 0.03) and determinants included diabetes mellitus (63% compared with 21%, P < 0.03), calcium deposition (58% compared with 5%, P < 0.003), smaller stent cross-sectional area (SA) (as demonstrated by post-stenting IVUS studies, 8.1 +/- 1.4 mm compared with 10.2 +/- 2.2 mm, P < 0.01), larger plaque burden (64 +/- 6% compared with 57 +/- 8%, P < 0.03) and less circular expansion at the aorto-coronary junction. Serial IVUS examination was performed in 11 patients with restenosis of the right coronary ostium. The mean reduction in the SA was 21% at the aorto-coronary junction (6.4 +/- 1.9 mm, P < 0.003), whereas the SA at the distal edge was unchanged. Thirty-three per cent of late luminal loss was due to chronic stent recoil. CONCLUSION: These findings suggest that stenosis of the right coronary ostium is a high-risk lesion for stent restenosis. In addition to excessive intimal growth, chronic stent recoil might be an important etiologic factor at this particular location.

Reactive hyperemia following coronary balloon angioplasty, but not dipyridamole-induced hyperemia, predicts resolution of exercise-induced ST-segment depression.

OBJECTIVES: To characterize delayed restoration of coronary blood flow following successful percutaneous transluminal coronary angioplasty (PTCA). BACKGROUND: Delayed restoration of coronary blood flow following successful PTCA is common and likely the result of multiple factors. Temporary myocardial ischemia and dipyridamole administration both result in increased coronary blood flow, but by different mechanisms. The relationship between these phenomena and exercise-induced ST-segment depression after PTCA was investigated to determine if any correlation existed. METHODS: Forty consecutive patients with single-vessel coronary artery disease underwent treadmill exercise testing before and after PTCA. The percentage change in coronary blood flow before and after 90 s balloon inflation was assessed. After a new steady state had been reached, dipyridamole was infused and changes in coronary blood flow were again determined. The relationship between changes in coronary blood flow and the presence of ST-segment depression during exercise testing after PTCA was determined. RESULTS: Peak coronary blood flow induced by reactive hyperemia was significantly greater than that in the steady state after balloon inflation (48.5+/-38.8 compared with 15.1+/-13.2 ml/min, P<0.0001). Dipyridamole administration also resulted in significant increases in coronary blood flow (15.1+/-13.2 ml/min compared with 31.0+/-24.9 ml/min, P<0.0001). ST-segment depression after PTCA was significantly less than before (0.10+/-0.07 mV compared with 0.19+/-0.08 mV, P<0.001). Further, reactive hyperemia, but not dipyridamole-induced hyperemia, correlated with attenuation of exercise-induced ST-segment depression after PTCA (r=0.62, P<0.0001). CONCLUSIONS: Reactive hyperemia following temporary coronary occlusion recreates local conditions associated with delayed resolution of myocardial ischemia following successful PTCA. Further, this phenomenon appears to be distinct from changes in coronary blood flow induced by dipyridamole.

Advancing age is associated with diminished vascular remodeling and impaired vasodilation in resistance coronary arteries.

BACKGROUND: Compensatory enlargement of the coronary arterial wall has been described in the early stages of native atherosclerosis. However, little is known about the specific effect of aging on this adaptive process in atherosclerosis. The purpose of the current study was to characterize the effects of advancing age on vascular remodeling and endothelium-dependent and -independent coronary vasodilation in patients without coronary artery disease risk factors. METHODS: Twenty-six patients without coronary risk factors and with normal and mildly diseased coronary arteries were studied. Vessel, lumen and atherosclerotic plaque areas were evaluated by intravascular ultrasound and coronary flow response was assessed using papaverine and acetylcholine in the left anterior descending coronary artery. RESULTS: There was a weak but significant correlation between plaque area and age (r = 0.29, P<0.01). Vessel area was also weakly but significantly correlated with age (r = 0.22, P<0.05). However, lumen area had no correlation with age. Vessel area in the younger group (<50 years) and the older group (> or =50 years) increased 1.64 and 0.55 mm2 for every 1 mm2 increase in plaque area (r = 0.62, P<0.0001 and r = 0.39, P<0.05, respectively). With regard to vascular reactivity, there was an inverse correlation between the percentage increases in coronary blood flow (CBF) evoked by acetylcholine and aging (r = -0.49, P<0.05). The percentage increases in CBF evoked by papaverine also inversely correlated with aging (r=-0.53, P<0.01). However, the percentage changes in coronary artery diameter evoked with acetylcholine did not correlate with aging. CONCLUSION: This study suggests that endothelium-dependent and -independent vasodilation of the resistance coronary artery are impaired with advancing age, which may be in association with attenuated coronary vascular remodeling with aging.

A new predictor of improvement in regional left ventricular function assessed by ST/HR slope derived from ST elevation on exercise testing in patients with healed myocardial infarction.

This study evaluates the clinical usefulness of ST/HR slope derived from ST elevation on exercise to predict the improvement in regional wall motion following coronary revascularization in patients with healed myocardial infarction. We studied 58 patients with a diseased, infarct-related and single-vessel coronary artery. The decline calculated from the final 12 data points relating ST-segment elevation to heart rate during exercise were derived (ST/HR slope). Hypokinesis in the infarcted region was assessed by the centerline method and expressed in terms of standard deviations (SD/chord). The increase more than 30% of the SD/chord, which was defined as the improvement in regional wall motion, was seen in 23 of the 30 patients with a ST/HR slope of > or = 5.0 (microV/bpm), and in 4 of the 28 patients with a ST/HR slope <5.0 (microV/bpm) (P <.0001). Thus, a ST/HR slope derived from ST elevation on exercise identifies subgroups of patients who show a good recovery of regional wall motion.