Impaired myocardial vasodilation during hyperemic stress with dipyridamole in hypertriglyceridemia

OBJECTIVES: This study sought to investigate the specific role of hypertriglyceridemia in the myocardial hyperemic stress with dipyridamole/rest flow ratio (MDR). BACKGROUND: Reduced MDR has been reported in hypercholesterolemic patients without evidence of ischemia. However, the specific role of hypertriglyceridemia in MDR has not been studied. METHODS: Fifteen nondiabetic normocholesterolemic hypertriglyceridemic patients and 13 age-matched control subjects were studied. Myocardial blood flow (MBF) during dipyridamole administration and baseline MBF in hypertriglyceridemic patients and control subjects were measured using positron emission tomography and nitrogen-13 ammonia, after which the MDR was calculated. RESULTS: Baseline MBF (ml/min per 100 g heart weight) in hypertriglyceridemic patients (mean +/- SD 73.6 +/- 24.1) did not differ significantly from that in control subjects (81.6 +/- 37.2). MBF during dipyridamole loading in hypertriglyceridemic patients (198 +/- 106) was significantly reduced compared with that in control subjects (313 +/- 176, p < 0.05), as was the MDR (2.71 +/- 1.07 vs. 3.73 +/- 1.14, respectively, p < 0.05). Spearman rank-order correlation analysis showed a significant relation between plasma triglyceride concentration and MDR (r = -0.466, asymptotic SE 0.157, p = 0.0125); however, no such significant relation was seen between total plasma cholesterol concentration and MDR (r = -0.369, asymptotic SE 0.130, p = 0.059). CONCLUSIONS: Impaired myocardial vasodilation was suggested in hypertriglyceridemic patients without symptoms and signs of ischemia.     

Acute myocardial infarction in a patient during dobutamine stress echocardiography

Combined chemotherapy/radiotherapy treatments appear to yield better results in locally advanced non-small-cell lung cancer (NSCLC) than radiotherapy alone. The optimal induction chemotherapy regimen remains to be established. In the present study, chemotherapy with cisplatin and vinorelbine was used prior to radical radiotherapy in Stage III-B NSCLC. Thirty-three patients were entered prospectively into a Phase II study. Treatment consisted of three cycles of chemotherapy with cisplatin 100 mg/m2 on day 1 and vinorelbine 30 mg/m2 on days 1 and 8, followed by thoracic radiotherapy (60 Gy). Twenty-two percent of the 33 patients had grade 3-4 leukopenia, and there were six episodes (in 4 patients) of neutropenia-associated fever. Gastrointestinal toxicity was generally moderate. Peripheral neuropathy was present in 42% of the patients, although in most of them it was slight. The main radiotherapy toxicity was esophagitis grade I-II. Evaluation of response after the third chemotherapy course showed an objective response in 16 patients (48%), whereas in three patients (9%) the disease progressed during therapy. The median survival of the entire group was 13 months. Cisplatin plus vinorelbine followed by radiotherapy is an effective schedule for patients with locally advanced non-small-cell lung cancer.     

Respiratory arrest during dipyridamole stress testing

There is an increasing usage of radionuclide scanning to assess myocardial perfusion, with dipyridamole, the most commonly used stress agent. Although this is an effective, and usually very safe, means by which to assess myocardial blood supply, there have been several incidents of acute bronchospasm in asthmatic patients. There have, however, been no previous reports of respiratory arrest occurring in patients with emphysema. This case illustrates the dangers of administering intravenous dipyridamole, or even adenosine, to patients with chronic lung disease.     

Detection of myocardial viability by stress echocardiography

Dobutamine echocardiography has gradually acquired a place among the currently available techniques to evaluate myocardial viability. It is a very efficient technique, easily accessible and inexpensive. It detects preservation of the myocyte contractile apparatus, which unlike other tests best assesses myocardial viability. Its value in stunned and hibernating myocardium is herein described.     

Cardiac asystole during dobutamine stress echocardiography

As hepatitis B vaccination is becoming generalized in Europe, cutaneous adverse events are being more frequently reported in the literature. We report the first case of generalized granuloma annulare following hepatitis B immunization. A 51-year-old woman presented a generalized granuloma annulare one month after the one-year booster injection of the hepatitis B vaccine. The lesions resolved with sulfone therapy. We observed an identical recurrence three weeks after the five-year booster.     

Comparison of myocardial contrast echocardiography and low-dose dobutamine stress echocardiography in predicting recovery of left ventricular function after coronary revascularization in chronic ischemic heart disease

BACKGROUND: Dobutamine stress echocardiography (DSE) and myocardial contrast echocardiography (MCE) can predict recovery of left ventricular function after myocardial infarction. DSE also has been shown to predict left ventricular functional recovery after revascularization in chronic ischemic heart disease, whereas MCE has not been evaluated in such patients. This study was performed to compare DSE and MCE in the prediction of left ventricular functional recovery after revascularization in patients with chronic ischemic heart disease. METHODS AND RESULTS: MCE and DSE were performed in 35 patients with chronic coronary artery disease and significant wall motion abnormalities (mean ejection fraction, 0.36 +/- 0.09). Regional wall motion was scored by use of a 16-segment model wherein 1 = normal or hyperkinetic, 2 = hypokinetic, 3 = akinetic, and 4 = dyskinetic. Each segment was evaluated for contractile reserve by DSE and perfusion by MCE. Revascularization (coronary artery bypass graft [n = 13] and percutaneous transluminal coronary angioplasty [n = 10]) was successful in 23 patients. Follow-up echocardiograms were done to assess wall motion 30 to 60 days later. In 238 segments with resting wall motion abnormalities, perfusion was more likely to present than contractile reserve (97% versus 91%, P < .02). Revascularization resulted in functional recovery in 77 of 95 hypokinetic segments (81%) but only 18 of 57 akinetic segments (32%, P < .0001). DSE and MCE were not significantly different in predicting functional recovery of hypokinetic segments. In akinetic segments, DSE and MCE had similar sensitivities (89% versus 94%, respectively) and negative predictive values (93% and 97%, respectively) in predicting functional recovery. However, DSE had a higher specificity (92% versus 67%, P < .02) and positive predictive value (85% versus 55%, P < .02) than MCE in predicting functional recovery. CONCLUSIONS: Both contractile reserve by DSE and perfusion by MCE are predictive of functional recovery in hypokinetic segments after coronary revascularization in patients with chronic coronary revascularization in patients with chronic coronary artery disease. In akinetic segments, myocardial perfusion by MCE may exist in segments that do not recover contractile function after revascularization. Thus, contractile reserve during low-dose dobutamine infusion is a better predictor of functional recovery after revascularization in akinetic segments than perfusion.     

Striking electrocardiographic changes associated with pheochromocytoma. Masquerading as ischemic heart disease

A patient with pheochromocytoma presented striking electrocardiographic changes mimicking ischemic heart disease at one time and acute pulmonary embolism at other times. Diffuse left ventricular hypokinesia was demonstrated in the presence of normal coronary arteries. Following removal of the pheochromocytoma, the electrocardiographic abnormalities disappeared.     

Apical hypertrophy with massive myocardial fibrosis: comparison with electrocardiographic changes

RESEARCH QUESTION: Although gait patterns of children are well described in gait analysis studies for barefoot gait, loading patterns in gait with shoes have not been analysed compared to barefoot gait. METHODS: 30 children (age 1.8 to 4.8 years) were examined. Ground reaction forces were recorded using two series connected Kistler plates, taking the 3D coordinates and the time coordinate. The gait aspect was recorded using a video system. Three shoe types were tested against each other and against barefoot gait. RESULTS: 1399 gait cycles, 739 barefoot, 660 with shoes were usable for calculation. Statistic analyses comparing barefoot gait to gait with shoes showed: A significant increase in ground contact duration, a shifting of maximal load from the rear towards the midfoot area, a significant increased maximal load, a cushioning of the initial impact at primary ground contact. A comparison between the shoes showed no significant influence of a medial subtalar orthotic support. CONCLUSION: Shoes cause a significant change of loading patterns. But there are also significant differences between different shoe types. CLINICAL RELEVANCE: Shoes for children must provide a stabilisation for the hindfoot, and must not restrict motion in the areas of the ankle and the metatatrsophalangeal joints. The amount of load in the different gait phases must be considered for the construction of a dynamic shoe for children.     

Subendocardial myocardial ischemia as assessed with myocardial contrast echocardiography in patients with ischemic heart diseases

Myocardial contrast echocardiography was used to characterize changes in the regional and transmural myocardial blood flow distribution that were provoked by rapid atrial pacing stress in patients with coronary artery diseases. In patients with coronary organic stenosis, a decrease in the myocardial contrast-enhancement in the subendocardial half after rapid atrial pacing was associated with stress-induced chest pain and electrocardiographic ST-T changes. The decrease in the myocardial contrast-enhancement in the subendocardial half after rapid atrial pacing was not observed in patients without coronary stenosis or after coronary angioplasty. Thus, the finding was considered to reflect myocardial ischemia. Pacing-induced decreases in myocardial contrast-enhancement were observed in some patients with old myocardial infarction and significant resting coronary collaterals. In these patients, myocardial ischemia was considered to have developed at rapid pacing because collateral function was good enough to perfuse the infarct myocardium at rest, but was not good enough to prevent myocardial ischemia at stress. Thus, myocardial contrast echocardiography seems to be particularly useful in assessing myocardial ischemia at stress due to coronary stenosis in patients with angina pectoris and due to poor dynamic collateral function in patients with old myocardial infarction.     

Combined low dose dipyridamole-dobutamine stress echocardiography to identify myocardial viability

OBJECTIVES: We sought to evaluate the effects of combined administration of infra-low dose dipyridamole and low dose dobutamine on assessment of myocardial viability. BACKGROUND: Low dose pharmacologic stress echocardiography with either dobutamine or dipyridamole infusion has been proposed for the recognition of myocardial viability. METHODS: Thirty-four patients with rest wall motion dyssynergy by two-dimensional echocardiography and with angiographically proved coronary artery disease underwent in combination with two-dimensional echocardiographic monitoring: 1) low dose (5 to 10 microgram/kg per min over 3 min) dobutamine infusion; 2) infra-low dose (0.28 mg/kg over 4 min) dipyridamole infusion; 3) combination of infra-low dose dipyridamole infusion immediately followed by low dose dobutamine infusion (combined dipyridamole-dobutamine). RESULTS: Follow-up rest echocardiography was available in 30 patients. After revascularization, 82 segments showed a contractile improvement of > or = 1 grade, whereas 63 segments remained unchanged. The sensitivity of dobutamine, dipyridamole and combined dipyridamole-dobutamine for predicting recovery was 72% (95% confidence interval [CI] 60.9% to 81.3%), 67% (CI 55.8% to 77%) and 94% (CI 86.3% to 97.9%), respectively. The specificity of dipyridamole, dobutamine and combined dipyridamole-dobutamine was 95% (CI 86.7% to 99%), 92% (CI 82.4% to 97.3%) and 89% (CI 78.4% to 95.4%), respectively. The accuracy of the dobutamine, dipyridamole and combined dipyridamole-dobutamine test was 80%, 79% and 92%, respectively (combined dipyridamole-dobutamine vs. dobutamine, p < 0.05; combined dipyridamole-dobutamine vs. dipyridamole, p < 0.01). CONCLUSIONS: Infra-low dose dipyridamole added to low dose dobutamine recruits an inotropic reserve in asynergic segments that were nonresponders after either dobutamine or dipyridamole alone and destined to recover after revascularization.     

Effects of beta-blockade and atropine on ischemic responses in left ventricular regions subtending coronary stenosis during dobutamine stress echocardiography

OBJECTIVES: This study was designed to examine the effects of a beta-adrenergic blocking agent on the ischemic response to dobutamine stress and to determine the degree to which these effects can be abolished by the addition of atropine. BACKGROUND: Whether beta-blockade affects the sensitivity of dobutamine stress echocardiography for the diagnosis of coronary artery disease has been controversial. METHODS: In nine pigs, a left anterior descending coronary artery stenosis was created to reduce flow reserve (maximal/rest flow) to 1.1 to 1.9 without baseline regional wall motion abnormalities. This corresponded to a 50% to 90% diameter stenosis. Wall thickening was measured using epicardial echocardiography. Regional lactate production and coronary venous pH were monitored from an adjacent cardiac vein. A standard protocol of dobutamine stress echocardiography was first performed. After normalization of the ischemic abnormalities elicited with this infusion, esmolol was infused at 50 micrograms/kg body weight per min and the dobutamine test was repeated, with 1.0 mg of atropine added at the maximal dobutamine dose. RESULTS: Without esmolol, dobutamine stress induced myocardial ischemia with a reduction in regional wall thickening and lactate production in all nine pigs. Multiple regression analysis revealed that coronary flow per heartbeat (p < 0.01) and lactate production (p < 0.05) independently correlated with regional wall thickening during dobutamine stress. The beta-blocker significantly reduced heart rate and regional oxygen consumption and altered the relation between coronary flow per heartbeat and regional wall thickening (p < 0.05) during dobutamine stress. Esmolol prevented dobutamine-induced ischemia (lactate production and wall motion abnormalities) in seven of nine pigs. The addition of atropine induced lactate production and a reduction in wall thickening in five of seven pigs in which ischemia had been prevented by beta-blockade. However, lactate production was higher and regional venous pH was lower with the baseline dobutamine infusion than with that performed after esmolol with atropine added at the maximal dobutamine dose (p < 0.05). CONCLUSIONS: A correlation between regional wall thickening and coronary flow per heartbeat was demonstrated during baseline dobutamine stress. Beta-blockade shifted this relation so that dobutamine stress-induced myocardial ischemia was attenuated. The mechanisms by which beta-blockade prevents dobutamine-induced ischemia appeared to be mainly through decreases in heart rate and rate of rise in left ventricular pressure, improvement of regional coronary flow per heartbeat and attenuation of regional ischemic lactate production. Adding atropine in conventional doses enhanced the ability of dobutamine stress to induce myocardial ischemia but did not completely abolish the effects of beta-blockade on either the severity of dobutamine-induced wall thickening abnormalities or regional metabolic disturbances.     

Noninvasive evaluation of myocardial ischemia in Kawasaki disease: comparison between dipyridamole stress thallium imaging and exercise stress testing

PURPOSE: Reduction of the frequency of injections and localization of the absorption of drug molecules to the injection site would be of great advantage in epidural pain treatment. The epidural use of a controlled release gel of lidocaine and ibuprofen was studied. METHODS: The effect of a poloxamer gel (25%) containing 2% lidocaine.HCl and 2% ibuprofen.Na on the duration of analgesia after epidural administration to pigs was compared with drug in solution. Analgesia was assessed by observing the motor function and the nociceptive reflex-withdrawal response to painful pressure stimulation on the feet. Pharmacokinetic and histological examinations were performed. RESULTS: Analgesia lasted significantly longer after epidural lidocaine gel injection in comparison with the solution. The gel prolonged the systemic absorption, thereby increasing the epidural availability of lidocaine for spinal analgesia. Although the absorption of ibuprofen was prolonged after epidural gel injection, the duration of analgesia as compared with the solution was not prolonged. After epidural injection, only slight inflammatory changes were observed in the tissue structures of the epidural space, but none in the spinal cord. CONCLUSIONS: These results demonstrate poloxamer gel to be a promising controlled-release, injectable epidural formulation for the management of pain.     

Syncope caused by cardiac asystole during dobutamine stress echocardiography

Syncope caused by cardiac asystole during dobutamine stress echocardiography occurred in a 60 year old woman presenting with chest pain and a non-diagnostic exercise test. Cardiac asystole was not associated with myocardial ischemia and was attributed to a powerful cardioinhibitory vagal reflex elicited by the stimulation by the drug of cardiac and aortic mechanoreceptors. Cardiac asystole was promptly reversed by the administration of atropine with no significant sequelae.     

Potential advantage of flash echocardiography for digital subtraction of B-mode images acquired during myocardial contrast echocardiography

Optimal assessment of myocardial perfusion with contrast echocardiography by using B-mode imaging often requires image alignment and background subtraction, which are time consuming and need extensive expertise. Flash echocardiography is a new technique in which primary images are gated to the electrocardiogram and secondary images are obtained by transmitting ultrasound pulses in rapid succession after each primary image. Myocardial opacification is seen in the primary image and not in the secondary images because of ultrasound-induced bubble destruction. Because the interval between the primary and first few secondary images is very short, cardiac motion between these images should be minimal. Therefore we hypothesized that 1 or more secondary images could be subtracted from the primary image without the need for image alignment. The ability of ultrasound to destroy microbubbles was assessed by varying the sampling rate, line density, and mechanical index in 6 open-chest dogs. The degree of translation between images was quantified in the x and y directions with the use of computer cross-correlation. At sampling rates of 158 Hz or less and a mechanical index of more than 0.6, videointensity rapidly declined to baseline levels by 25 ms. Significant translation between images was noted only at intervals of more than 112 ms. It is concluded that flash echocardiography can be used for digital subtraction of baseline from contrast-enhanced B-mode images without image alignment. Background subtraction is therefore feasible on-line, potentially eliminating the need for off-line image processing in the future.     

Comparative prognostic value of clinical risk indexes, resting two-dimensional echocardiography, and dipyridamole stress thallium-201 myocardial imaging for perioperative cardiac events in major nonvascular surgery patients

The relative prognostic value of widely accessible resting two-dimensional echocardiographic ventricular function data has not been compared with recognized clinical and scintigraphic risk markers in patients who are unable to exercise before major nonvascular surgery. To this end, 53 consecutive patients aged 67 +/- 13 years undergoing preoperative evaluation (intraabdominal, 23%; orthopedic, 30%; thoracic, 9%; other, 38%) for known or suspected coronary artery disease were followed up to evaluate the prognostic value of these studies for the perioperative cardiac events (cardiac death [n = 4], myocardial infarction [n = 2], unstable angina [n = 3], and pulmonary edema [n = 8]) that occurred in 13 of the 53 patients (25%). Dipyridamole thallium-201 myocardial redistribution defects occurred in 15 (28%) patients. Resting echocardiographic left ventricular dysfunction was present in 21 (40%) patients. Multivariate analysis of clinical, echocardiographic, and scintigraphic risk predictors revealed that cardiac events were not predicted by clinical variables, including Goldman class or score. Cardiac events were independently predicted only by the presence of significant left ventricular dysfunction on resting two-dimensional echocardiography (p < 0.042) and dipyridamole thallium-201 defect redistribution (p < 0.026). A dipyridamole-induced reversible thallium-201 perfusion defect was predictive of subsequent cardiac death or myocardial infarction (p < 0.02), whereas left ventricular dysfunction on resting echocardiography was predictive of perioperative pulmonary edema (p < 0.023). We conclude that stress thallium-201 perfusion imaging and resting two-dimensional echocardiography provide independent prognostic information in patients undergoing major nonvascular surgery who are at significant risk for ischemic cardiac events and who are unable to perform standard exercise stress tests.(ABSTRACT TRUNCATED AT 250 WORDS)     

Age-related changes of electrocardiographic wave

OBJECTIVE: Cystic tumors of the adrenal gland are uncommon, but are being increasingly more frequently diagnosed during routine radiological evaluation as "incidentalomas". We discuss the differential diagnosis, therapeutic approach and the existing controversies concerning the management of this tumor type. METHODS: Two additional cases of adrenal pseudocyst in two women aged 47 and 38 years are presented. In one case the tumor was discovered incidentally, whereas the other case presented with acute pain arising from intracystic hemorrhage. RESULTS: The fist patient had a cystic tumor of 8 cm with some inner walls. Fine needle aspiration biopsy revealed a benign cystic lesion of the right adrenal gland. At laparotomy, an 8.5 x 4.5 cm multiloculated cystic lesion was excised. The second patient presented with abdominal pain due to intracystic hemorrhage. A Doppler US did not disclose any vessel inside the lesion. We performed a lumbotomy and excised a 7.5 x 6 cm cystic tumor located in the right adrenal gland. Both lesions were diagnosed as adrenal pseudocyst; the second case was a hemorrhagic one. CONCLUSIONS: The therapeutic approach in adrenal cystic tumors can be based upon the radiological and cytological findings since malignant cystic tumors are uncommon. A clear liquid and a negative cytology practically discard malignant tumors. Furthermore, cystic adenocarcinomas are usually large and the cystic liquid is cloudy with abundant cellularity. Surgical treatment is justified in the symptomatic, big or complex tumors (mixed, non-homogeneous).     

Effect of ischemic preconditioning on myocardial oxygen consumption during ischemia

Ischemic preconditioning (IPC) in the heart may reduce myocardial energy demand. The present study was undertaken to examine changes in myocardial oxygen consumption (MVO2) during ischemia by IPC in Langendorff perfused rat hearts. We assessed MVO2 during ischemia from the measurement of mitochondrial cyt. aa3 redox state by a two-wavelength reflectance spectrophotometry where T(1/2), the time from the onset of ischemia to the point for half reduction of cyt. aa3, was assumed to represent MVO2. The heart was preconditioned by three cycles of 5 min ischemia plus 5 min reperfusion and then subjected to 30 min global ischemia followed by reperfusion for 30 min. The T(1/2) was significantly longer in the preconditioned heart (30 +/- 6 s, n = 10) than the control heart (14 +/- 5 s, n = 9, P<0.001), indicating a reduction of MVO2 during ischemic period by IPC. The prolongation of T(1/2) was evident after only one IPC episode. When the heart was perfused with high K+ solution to abolish MVO2 for contractions, we still found the prolongation of T1(1/2) in the preconditioned heart (116 +/- 12 s, n = 6) compared to the control heart (86 +/- 10 s, n = 6, P<0.01), suggesting that decrease in contractile activity may be, in part but not completely, responsible for the reduction of MVO2. In contrast, the prolongation of T(1/2) was completely abolished by administration of a NO synthase inhibitor N omega-nitro-L-arginine in the high K+ arrested heart, demonstrating involvement of NO in the reduction of MVO2, presumably by suppression of mitochondrial respiratory chain. In conclusion, IPC reduces MVO2 during ischemia. The reduction of MVO2 in the preconditioned heart may be accounted for by decreased contractile activity and by depression of respiratory chain by NO.     

Dipyridamole stress echocardiography and exercise testing for risk stratification after uncomplicated myocardial infarction

BACKGROUND: Risk stratification for subsequent cardiac events after an acute infarction can be obtained by exercise testing or dipyridamole stress echocardiography. It remains to be determined whether these modalities are equivalent and provide incremental information on top of clinical evaluation. The aim of our study was to compare the prognostic information obtained early after an acute uncomplicated myocardial infarction of high dose dipyridamole coupled with echocardiography (stress echo) or maximal symptom-limited exercise testing. METHODS AND RESULTS: Ninety patients underwent dipyridamole stress echo and exercise testing at a mean +/- SD of 9 +/- 4 days after admission for acute uncomplicated first myocardial infarction. All patients were prospectively followed for 22 +/- 16 months. There were 9 hard events (3 cardiac deaths and 6 acute myocardial infarctions) and 12 soft events due to post MI angina (6 angioplasty and 6 bypass surgery procedures). Univariate predictor of hard events was rest-stress wall motion score index variation (p = 0.009); univariate predictors of all events (hard + soft) were: positive exercise testing (p = 0.001), positive stress echo (p = 0.001), rest-stress wall motion score index variation (p = 0.002), extent of ischemia at echo (p = 0.008). Multivariate analysis by Cox selected a non-Q wave infarction and rest-stress wall motion score index variation as predictors of death or reinfarction (overall chi-square for the model 12.2, p = 0.0022). CONCLUSIONS: Stress echo is superior to ergometric variables for predicting events after uncomplicated myocardial infarction.