Cardiogenic shock due to tachycardiomyopathy after heart transplantation: successful treatment with ivabradine.

Tachycardia-induced cardiomyopathy refers to an impairment in left-ventricular function due to chronic or prolonged tachycardia. We describe a heart transplant patient who developed cardiogenic shock due to tachycardia-induced cardiomyopathy. Low-output failure was further aggravated by administration of a short-acting beta-blocker during invasive hemodynamic monitoring. In contrast, heart rate control by administration of increasing doses of ivabradine supported recovery from cardiogenic shock and led to an improvement in the patient's clinical condition as well as left-ventricular function during follow-up.

[Heart disease in pregnancy]. / Herzerkrankungen in der Schwangerschaft.

During pregnancy, the changes of cardiovascular physiology can impose additional load and risk on the cardiovascular system of women with heart disease. Care of women with heart disease and childbearing potential should include preconception risk stratification and counselling. Risk stratification rests on a carefully obtained history and examination, electrocardiography and echocardiography. Exercise capacity is an important predictor of maternal cardiovascular events. High-risk conditions include severe pulmonary hypertension, cyanotic lesions, severe left ventricular obstruction and aortic disease in Marfan-Syndrome. High-risk patients should be referred to and cared for by tertiary centres. A multidisciplinary team approach with cardiologists, obstetricians and anaesthetists during pregnancy, delivery and the postpartum period is recommended. Meticulous attention should be paid to effective anticoagulation for prosthetic heart valves. Risks and benefits of the anticoagulation strategy should be fully discussed with the patient. Peripartal cardiomyopathy is a disease that occurs during he late stages of pregnancy and the peripartum period and is associated with congestive heart failure, thrombembolism, cardiac death and recurrence in subsequent pregnancies. Dilated cardiomyopathy with impaired functional reserve or markedly impaired left ventricular function constitutes a high risk for the pregnant women. In addition to sodium restriction, treatment of heart failure consists of loop diuretics, vasodilators, digoxin and beta-blockers, if appropriate. Coronary heart disease and myocardial infarction are rare during pregnancy but should be considered in women with chest pain. Pharmacological therapy of rhythm disorders should be reserved for arrhythmias resulting in maternal or fetal hemodynamic compromise and for arrhythmias with intolerable symptoms.

Quantification of left ventricular volumes and ejection fraction from 16- and rebinned 8-frame gated 99mTc-tetrofosmin SPECT. Comparison of 4D-MSPECT and QGS.

AIM: Using 8-frames/cardiac cycle with gated SPECT underestimates end-diastolic volumes (EDV) and ejection fractions (LVEF), and overestimates end-systolic volumes (ESV). However, using 16-frames/cardiac cycle significantly decreases the signal-to-noise-ratio. We analyzed 16-frames and rebinned 8-frame gated SPECT data using common 4D-MSPECT and QGS algorithms. PATIENTS, METHODS: 120 patients were examined using gated SPECT on a Siemens Multispect 3 (triple-head gamma camera) 60 minutes after intravenous administration at rest of about 450 MBq (two-day protocol) or about 750 MBq (one-day protocol) (99m)Tc-tetrofosmin. Reoriented short axis slices (16-frames) were summed framewise (1+2,3+4, etc.) yielding 8-frame data sets. EDV, ESV and LVEF were calculated for both data sets using 4D-MSPECT and QGS. RESULTS: QGS succeeded with 119, 4D-MSPECT with 117 patients. For the remaining 116 patients, higher EDV (+0.8ml/+3.8 ml) and LVEF (+1.5%/+2.6%; absolute) and lower ESV (-1.7ml/-0.9 ml) (4D-MSPECT/QGS) were found for 16-frame runs. Bland-Altman limits were smaller for QGS than 4D-MSPECT [EDV 32/12 ml, ESV 21/10 ml, LVEF 17/7% (4D-MSPECT/QGS)]. CONCLUSION: Both algorithms showed the expected effects. Contour finding using QGS failed with only one data set, whereas contour finding using 4D-MSPECT failed with three data sets. Since the effects observed between the 8- and the 16-frame studies are relatively small and quite predictable, 8-frame studies can be employed in clinical routine with hardly any loss at all, plus contour finding appears less susceptible to error.

Dipyridamole/aspirin combination in secondary stroke prevention: effects on absolute myocardial blood flow and coronary vascular resistance.

OBJECTIVE: In the European Stroke Prevention Study (ESPS 2), oral administration of a fixed combination of 200 mg extended-release dipyridamole and 25 mg aspirin (twice daily) after ischemic stroke or transient ischemic attack, significantly reduced the risk of stroke compared to placebo as well as compared to aspirin or dipyridamole alone. However, the i.v. application of dipyridamole over 4 - 6 min is known to increase myocardial blood flow up to 6-fold, and thereby potentially provoke ischemic wall motion abnormalities in patients with coronary artery disease. We therefore assessed the cardiac side effects of the dipyridamole/aspirin combination on absolute myocardial blood flow (MBF) and coronary vascular resistance (CVR). METHODS: MBF and CVR were measured using 150-water positron emission tomography in 24 patients after stroke or transient ischemic attack, before and 6.7 +/- 1.9 days after starting the dipyridamole/aspirin combination (Aggrenox) therapy. RESULTS: Resting MBF increased by 39% (max. 112%), from 0.92 +/- 0.13 (ml x g(-1) x min(-1)) at baseline to 1.28 +/- 0.27 (ml x g(-1) x min(-1)) under ongoing dipyridamole/aspirin combination therapy (p < 0.0005). CVR consecutively decreased from 105.3 +/- 16.9 to 74.1 +/- 16.5 (mmHg x ml(-1) x g x min) (p < 0.0005). The relative increase in MBF correlated negatively with the body surface area. No correlation was found between relative MBF increase and duration of dipyridamole/aspirin combination therapy (range 4 - 10 days). CONCLUSIONS: Orally administered dipyridamole/aspirin combination therapy in secondary stroke prevention increases MBF and decreases CVR significantly. These cardiac side effects of the dipyridamole/aspirin combination should be taken into account in stroke patients with proven or suspected coronary artery disease, particularly in combination with a small body surface area.

Identification and characterization of errors and incidents in a medical intensive care unit.

BACKGROUND: To assess the frequency, type, consequences, and associations of errors and incidents in a medical intensive care unit (ICU). METHODS: Two-hundred and sixteen consecutive patients with predominantly cardiovascular and pulmonary disorders admitted between December 2002 and February 2003 were enrolled. Demographic data, SAPS II, and TISS-28 were obtained for all patients. Prior to patient enrolment all staff members (physicians, nurses, physiotherapists) were repeatedly encouraged to make use of the Incident Report Form (IRF) and detailed descriptions on how, why and when to use the IRF were provided. RESULTS: During the observation period of 64 days, 50 errors involving 32 patients (15%) were reported. Patients subjected to errors were more severely ill (SAPS II 42 +/- 25 vs. 32 +/- 18, P < 0.05), had a higher hospital mortality (38% vs. 9%), and a longer ICU stay (11 +/- 18 vs. 3 +/- 5 days, P < 0.05). Gender, age and TISS-28 were equally distributed. Each day of ICU stay increased the risk by 8% (odds ratio 1.078, 95% confidence interval 1.034-1.125, P < 0.001), and by 2.3% per SAPS II point (odds ratio 1.023, 95% confidence interval 1.006-1.040, P < 0.001). The majority of errors and incidents were judged as 'human failures' (73%), and 46 errors and incidents (92%) as 'avoidable'. CONCLUSIONS: The identification and characterization of errors and incidents combined with contextual information is feasible and may provide sufficient background information for areas of quality improvement. Areas with a high frequency of errors and incidents need to undergo process evaluation to avoid future occurrence.

[Cardiogenic shock in a 61 year old female with recurrent panic attacks]. / Kardiogener Schock bei 61-jähriger Patientin mit rezidivierenden Panikattacken.

A 61 year old patient in a severely reduced general condition complaining of epigastric pain was admitted to our emergency room. Because of elevated troponin T and creatine kinase levels and severely reduced left ventricular function as seen in echocardiography as well as negative T-waves in the anterolateral ECG leads we suspected an acute coronary syndrome. The patient underwent coronary angiography after intubation and a coronary artery disease was excluded. The initial therapy included the use of an intraaortic balloon pump, volume and catecholamine administration controlled by a pulmonary artery catheter. Conducting an abdominal ultrasound we detected a mass at the right adrenal gland. The suspected diagnosis of pheochromocytoma was confirmed by elevated catecholamine levels in the urine and a CT scan. After recompensation and subsequent administration of phenoxybenzamine a benign pheochromocytoma was resected. A massive catecholamine secretion due to a pheochromocytoma can lead to a cardiogenic shock and multiple organ failure. In patients with recurrent panic attacks and hypertension a pheochromocytoma should be included in the differential diagnosis.

Superiority of sirolimus eluting stent compared with intracoronary beta radiation for treatment of in-stent restenosis: a matched comparison.

OBJECTIVE: To compare acute and follow up clinical and angiographic results after treatment of in-stent restenosis (ISR) by sirolimus eluting stents (SES) with results obtained after intracoronary radiation therapy (IRT). DESIGN: Matched pair analysis. METHODS: 62 consecutive ISR lesions (< 30 mm lesion length, reference diameter < 3.5 mm) in 62 patients were treated with SES. From a database of 174 lesions (n = 141 patients) treated for ISR by intracoronary beta radiation, 62 lesions (62 patients) were pair matched with the SES group for diabetes mellitus, lesion length, vessel size, and pattern of ISR. Six month angiographic and 12 month clinical follow up results were obtained. RESULTS: Baseline clinical and angiographic characteristics were similar between the groups (not significant). SES implantation resulted in significantly lower postprocedural in-lesion diameter stenosis than did IRT (mean (SD) 14.2 (9.5)% v 21.1 (10.6)%, p = 0.001), significantly higher minimum lumen diameter at follow up (1.91 (0.58) v 1.55 (0.72) mm, p = 0.005), and a higher net gain (1.16 (0.55) v 0.77 (0.70) mm, p = 0.002). Angiographic binary in-lesion restenosis rate at six months was 11% in the SES group and 29% in the IRT group (p = 0.046). In 16 ISR lesions SES were used after failed IRT and in 46 lesions for first time ISR. In-lesion late loss was higher after use of SES for failed IRT than after use of SES for first time ISR (0.61 (0.67) mm v 0.24 (0.41) mm, p = 0.018). In a multivariate analysis prior failed IRT was the only independent predictor for recurrent restenosis after SES for ISR (p = 0.052, odds ratio 5.8). Six patients (10%) in the SES group and 17 patients (27%) in the IRT group underwent target lesion revascularisation during the 12 months of follow up (p = 0.022). CONCLUSIONS: In this non-randomised matched cohort SES achieved acute and follow up results superior to IRT for treatment of ISR even if cases of failed IRT are included. Failed IRT is a predictor of impaired SES effectiveness.

[An approach for comparative quantification of myocardial blood flow (O-15-H2O-PET), perfusion (Tc-99m-tetrofosmin-SPECT) and metabolism (F-18-FDG-PET)]. / Eine Methode zur vergleichenden Quantifizierung von myokardialem Blutfluss (0-15-H2O-PET), Perfusion (Tc-99m-Tetrofosmin-SPECT) und Stoffwechsel (F-18-FDG-PET).

AIM: In the present study a new approach has been developed for comparative quantification of absolute myocardial blood flow (MBF), myocardial perfusion, and myocardial metabolism in short-axis slices. METHODS: 42 patients with severe CAD, referred for myocardial viability diagnostics, were studied consecutively with 0-15-H2O PET (H2O-PET) (twice), Tc-99m-Tetrofosmin SPECT (TT-SPECT) and F-18-FDG PET (FDG-PET). All data sets were reconstructed using attenuation correction and reoriented into short axis slices. Each heart was divided into three representative slices (base, midventricular, apex) and 18 ROIs were defined on the FDG PET images and transferred to the corresponding H2O-PET and TT-SPECT slices. TT-SPECT and FDG-PET data were normalized to the ROI showing maximum perfusion. MBF was calculated for all left-ventricular ROIs using a single-compartment-model fitting the dynamic H2O-PET studies. Microsphere equivalent MBF (MBF_micr) was calculated by multiplying MBF and tissue-fraction, a parameter which was obtained by fitting the dynamic H2O-PET studies. To reduce influence of viability only well perfused areas (> 70% TT-SPECT) were used for comparative quantification. RESULTS: First and second mean global MBF values were 0.85 ml x min-1 x g-1 and 0.84 ml x min-1 x g-1, respectively, with a repeatability coefficient of 0.30 ml x min-1 x g-1. After sectorization mean MBF_micr was between 0.58 ml x min-1 x ml-1 and 0.68 ml x min-1 x ml-1 in well perfused areas. Corresponding TT-SPECT values ranged from 83% to 91%, and FDG-PET values from 91% to 103%. All procedures yielded higher values for the lateral than the septal regions. CONCLUSION: Comparative quantification of MBF, MBF_micr, TT-SPECT perfusion and FDG-PET metabolism can be done with the introduced method in short axis slices. The obtained values agree well with experimentally validated values of MBF and MBF_micr.

Electromechanical assessment of left ventricular function following successful percutaneous coronary revascularization.

Percutaneous electromechanical mapping was applied to evaluate the impact of coronary revascularization on electrical and mechanical parameters in patients with prior myocardial infarction. In 15 patients with prior (> or = 4 weeks) myocardial Q-wave infarction and regional wall motion abnormalities, left ventricular endocardial mapping was performed immediately prior to percutaneous coronary revascularization. Patients underwent repetitive mapping during 6-month follow-up angiography with good revascularization results in all patients. Mean regional unipolar electrogram (UP) amplitude of all regions remained unchanged (10.4 +/- 4.2 mV prerevascularization vs. 10.2 +/- 4.4 mV postrevascularization), whereas mean local shortening (LS) of all regions increased from 6.0% +/- 5.8% to 9.7% +/- 5.3% (P < 0.001). The percentage of electromechanical match regions (LS < 6% and UP < 9 mV) remained unchanged after revascularization (15% vs. 10%; NS), whereas the percentage of mismatch regions (LS < 6% and UP > 9 mV) declined from 38% to 10% (P < 0.0001). We conclude that electromechanical mapping allows the sensitive detection of improved mechanical function after successful revascularization. Electrical activity remains unchanged 6 months after revascularization and the number of regions with an electromechanical mismatch decrease.

Myocardial viability assessment by endocardial electroanatomic mapping: comparison with metabolic imaging and functional recovery after coronary revascularization.

OBJECTIVES: The objective of this study was to compare electroanatomic mapping for the assessment of myocardial viability with nuclear metabolic imaging using positron emission computed tomography (PET) and with data on functional recovery after successful myocardial revascularization. BACKGROUND: Animal experiments and first clinical studies suggested that electroanatomic endocardial mapping identifies the presence and absence of myocardial viability. METHODS: Forty-six patients with prior (> or =2 weeks) myocardial infarction underwent fluorine-18 fluorodeoxyglucose (FDG) PET and Tc-99m sestamibi single-photon emission computed tomography (SPECT) before mapping and percutaneous coronary revascularization. The left ventricular endocardium was mapped and divided into 12 regions, which were assigned to corresponding nuclear regions. Functional recovery using the centerline method was assessed in 25 patients with a follow-up angiography. RESULTS: Regional unipolar electrogram amplitude was 11.0 mV +/- 3.6 mV in regions with normal perfusion, 9.0 mV +/- 2.8 mV in regions with reduced perfusion and preserved FDG-uptake and 6.5 mV +/- 2.6 mV in scar regions (p < 0.001 for all comparisons). At a threshold amplitude of 7.5 mV, the sensitivity and specificity for detecting viable (by PET/SPECT) myocardium were 77% and 75%, respectively. In infarct areas with electrogram amplitudes >7.5 mV, improvement of regional wall motion (RWM) from -2.4 SD/chord +/- 1.0 SD/chord to -1.5 SD/chord +/- 1.1 SD/chord (p < 0.01) was observed, whereas, in infarct areas with amplitudes <7.5 mV, RWM remained unchanged at follow-up (-2.3 SD/chord +/- 0.7 SD/chord to -2.4 SD/chord +/- 0.7 SD/chord). CONCLUSIONS: These data suggest that the regional unipolar electrogram amplitude is a marker for myocardial viability and that electroanatomic mapping can be used for viability assessment in the catheterization laboratory.

Electromechanical mapping of the heart.

Electromechanical endocardial mapping of the heart using a nonfluoroscopic catheter-based system is a new imaging modality that has been studied recently in the experimental setting as well as in patients. Besides its original application in the diagnosis and treatment of various cardiac arrhythmias, it has also been used as an investigational tool for assessing left ventricular function and viability. Finally, the mapping system may be a valuable platform for direct myocardial revascularization using either laser treatment or injection of pharmacologic agents.

Gastric tonometry in patients with cardiogenic shock and intra-aortic balloon counterpulsation.

OBJECTIVE: To study the course of gastric regional PCO2 (PrCO2) in patients with cardiogenic shock requiring intra-aortic balloon (IAB) counterpulsation and the prognostic value of PrCO2 in this patient population. DESIGN: A prospective, observational clinical study. SETTING: Medical intensive care unit in a university hospital. PATIENTS: Twenty-six consecutive patients with cardiogenic shock requiring mechanical support with an IAB counterpulsation undergoing mechanical ventilation INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULT: Hemodynamic variables, tonometric variables, arterial blood gases, and arterial lactate were assessed before insertion of IAB (baseline), and 1, 2, 3, 8, 16, 24, and 48 hrs thereafter. A subset of these patients (n = 14) were studied just before and 1, 8, 24, and 32 hrs after IAB removal; 12/26 patients (46.2%) died. Cardiac index increased from baseline to 1 hr after insertion of IAB (1.7 +/- 0.3 to 2.6 +/- 0.8 L/min/m2, p < .05). PrCO2 did not change between admission (47 +/- 13 torr [6.3 +/- 1.7 kPa]) and 8 hrs after placement of IAB but increased to 63 +/- 22 torr (8.4 +/- 2.9 kPa) at 16 hrs (p < .05) without any further alteration until 48 hrs. CO2 gap showed a similar pattern with 15 +/- 11 torr (2.0 +/- 1.5 kPa) at baseline and an increase to 28 +/- 22 torr (3.7 +/- 2.9 kPa) 16 hrs later. PrCO2 and CO2 gap remained at high levels (59 +/- 11 torr [7.7 +/- 1.5 kPa] and 22 +/- 10 torr [2.9 +/- 1.3 kPa], respectively), before IAB removal without further improvement or deterioration thereafter. PrCO2 values showed no difference between survivors and nonsurvivors at any time point. CONCLUSION: Patients with cardiogenic shock developed high PrCO2 within the first 24 hrs, which reflects gastric mucosal ischemia. Persistently high levels of PrCO2 were indicative for prolonged hypoperfusion of the gut. Gastric tonometry failed to discriminate between survivors and nonsurvivors.

Evaluation of the SOFA score: a single-center experience of a medical intensive care unit in 303 consecutive patients with predominantly cardiovascular disorders. Sequential Organ Failure Assessment.

OBJECTIVE: To evaluate the use of the Sequential Organ Failure Assessment (SOFA) score, the total maximum SOFA (TMS) score, and a derived variable, the deltaSOFA (TMS score minus total SOFA score on day 1) in medical, cardiovascular patients as a means for describing the incidence and severity of organ dysfunction and the prognostic value regarding outcome. DESIGN: Prospective, clinical study. SETTING: Medical intensive care unit in a university hospital. PATIENTS: A total of 303 consecutive patients were included (216 men, 87 women; mean age 62 +/- 12.6 years; SAPS II 26.2 +/- 12.7). They were evaluated 24 h after admission and thereafter every 24 h until ICU discharge or death between November 1997 and March 1998. Readmissions and patients with an ICU stay shorter than 12 h were excluded. MAIN OUTCOME MEASURE: Survival status at hospital discharge, incidence of organ dysfunction/failure. INTERVENTIONS: Collection of clinical and demographic data and raw data for the computation of the SOFA score every 24 h until ICU discharge. MEASUREMENTS AND MAIN RESULTS: Length of ICU stay was 3.7 +/- 4.7 days. ICU mortality was 8.3% and hospital mortality 14.5%. Nonsurvivors had a higher total SOFA score on day 1 (5.9 +/- 3.7 vs. 1.9 +/- 2.3, p < 0.001) and thereafter until day 8. High SOFA scores for any organ system and increasing number of organ failures (SOFA score > or = 3) were associated with increased mortality. Cardiovascular and neurological systems (day 1) were related to outcome and cardiovascular and respiratory systems, and admission from another ICU to length of ICU stay. TMS score was higher in nonsurvivors (1.76 +/- 2.55 vs. 0.58 +/- 1.39, p < 0.01), and deltaSOFA/total SOFA on day 1 was independently related to outcome. The area under the receiver-operating characteristic curve was 0.86 for TMS, 0.82 for SOFA on day 1, and 0.77 for SAPS II. CONCLUSIONS: The SOFA, TMS, and deltaSOFA scores provide the clinician with important information on degree and progression of organ dysfunction in medical, cardiovascular patients. On day 1 both SOFA score and TMS score had a better prognostic value than SAPS II score. The model is closely related to outcome and identifies patients who are at increased risk for prolonged ICU stay.

Severe transmyocardial ischemia in a patient with tension pneumothorax.

OBJECTIVE: To report tension pneumothorax (TP) as a cause of severe myocardial ischemia. DESIGN: Clinical case report. SETTING: Medical intensive care unit of a university hospital. PATIENTS: One patient with severe shock attributable to right TP after unsuccessful percutaneous central venous catheterization. INTERVENTIONS: Blood pressure, electrocardiogram (ECG), chest radiograph, and echocardiography during and after shock. MEASUREMENTS AND MAIN RESULTS: On admission the patient was in profound state of shock (heart rate 140 beats/min, blood pressure 65/30 mm Hg). Twelve-lead ECG showed pronounced ST segment elevation in leads II, III, aVF, and V4-V6. Chest radiograph revealed right TP with complete displacement of the mediastinum and the heart to the left side. Immediate right-sided tube thoracostomy resulted in reexpansion of the lung followed by instantaneous hemodynamic and respiratory improvement as well as nearly complete resolution of the ECG changes. Peak value of the creatine phosphokinase was 4140 U/L without significant elevation of the MB isoenzyme at any time. Moreover, the initial hypokinesia of the posterior and lateral left ventricular wall resolved completely, as demonstrated by echocardiography. CONCLUSION: The specific condition of TP may lead to impaired systolic and diastolic coronary artery blood flow affecting ventricular repolarization and T-wave configuration in ECG indicative of transmyocardial ischemia. General symptoms, namely hypotension, tachycardia, and hypoxemia, are likewise typical for cardiogenic shock attributable to myocardial infarction. Yet any therapeutic measure directed toward revascularization, such as thrombolysis or even percutaneous transluminal coronary angioplasty, would have had devastating consequences. Therefore, thorough physical examination of our patient was pivotal in disclosing the true origin of profound shock.

Clinical and angiographic predictors of recurrent restenosis after percutaneous transluminal rotational atherectomy for treatment of diffuse in-stent restenosis.

Due to the widespread use of stents in complex coronary lesions, stent restenosis represents an increasing problem, for which optimal treatment is under debate. "Debulking" of in-stent neointimal tissue using percutaneous transluminal rotational atherectomy (PTRA) offers an alternative approach to tissue compression and extrusion achieved by balloon angioplasty. One hundred patients (70 men, aged 58 +/- 11 years) with a first in-stent restenosis underwent PTRA using an incremental burr size approach followed by adjunctive angioplasty. The average lesion length by quantitative angiography was 21 +/- 8 mm (range 5 to 68) including 22 patients with a length > or = 40 mm. Twenty-nine patients had complete stent occlusions with a lesion length of 44 +/- 23 mm. Baseline diameter stenosis measured 78 +/- 17%, was reduced to 32 +/- 9% after PTRA, and further reduced to 21 +/- 10% after adjunctive angioplasty. Primary PTRA was successful in 97 of 100 patients. Clinical success was 97%, whereas 2 patients developed non-Q-wave infarctions without clinical sequelae. Clinical follow-up was available for all patients at 5 +/- 4 months without any cardiac event. Angiography in 72 patients revealed restenosis in 49%, with necessary target lesion reintervention in 35%. The incidence of rerestenosis correlated with the length of the primarily stented segment and the length of a first in-stent restenosis. Thus, PTRA offers an alternative approach to treat diffuse in-stent restenosis. Neointimal debulking of stenosed stents can be achieved effectively and safely. PTRA resulted in an acceptable recurrent restenosis rate in short and modestly diffuse lesion, whereas the restenosis rate in very long lesions remains high despite debulking.

Influence of a platelet GPIIb/IIIa receptor antagonist on myocardial hypoperfusion during rotational atherectomy as assessed by myocardial Tc-99m sestamibi scintigraphy.

OBJECTIVES: This study evaluated the effect of the glycoprotein IIb/IIIa (GPIIb/IIIa) antagonist abciximab on myocardial hypoperfusion during percutaneous transluminal rotational atherectomy (PTRA). BACKGROUND: PTRA may cause transient ischemia and periprocedural myocardial injury. A platelet-dependent risk of non-Q-wave infarctions after directional atherectomy has been described. The role of platelets for the incidence and severity of myocardial hypoperfusion during PTRA is unknown. METHODS: Seventy-five consecutive patients with complex lesions were studied using resting Tc-99m sestamibi single-photon emission computed tomography prior to PTRA, during, and 2 days after the procedure. The last 30 patients received periprocedural abciximab (group A) and their results were compared to the remaining 45 patients (group B). For semiquantitative analysis, myocardial perfusion in 24 left ventricular regions was expressed as percentage of maximal sestamibi uptake. RESULTS: Baseline characteristics did not differ between the groups. Transient perfusion defects were observed in 39/45 (87%) patients of group B, but only in 10/30 (33%) patients of group A (p < 0.001). Perfusion was significantly reduced during PTRA in 3.3 +/- 2.5 regions in group B compared to 1.4 +/- 2.5 regions in group A (p < 0.01). Perfusion in the region with maximal reduction during PTRA in groups B and A was 76 +/- 15% and 76 +/- 15% at baseline, decreased to 56 +/- 16% (p < 0.001) and 67 +/- 14%, respectively, during PTRA (p < 0.01 A vs. B), and returned to 76 +/- 15% and 80 +/- 13%, respectively, after PTRA. Nine patients in group B (20%) and two patients in group A (7%) had mild creatine kinase and/or troponin t elevations (p = 0.18). Patients with elevated enzymes had larger perfusion defects than did patients without myocardial injury (4.2 +/- 2.7 vs. 2.3 +/- 2.5 regions, p < 0.05). CONCLUSIONS: These data indicate that GPIIb/IIIa blockade reduces incidence, extent and severity of transient hypoperfusion during PTRA. Thus, platelet aggregation may play an important role for PTRA-induced hypoperfusion.

[Diagnosis of myocardial viability in chronic myocardial ischemia with nuclear medicine techniques]. / Diagnostik der Myokardvitalität bei chronischer Myokardischämie mit nuklearmedizinischen Verfahren.

Non-invasive methods to identify absent or persistent myocardial viability have gained increasing importance in the therapeutic management and risk stratification of patients with ischemic left ventricular dysfunction. Myocardial scintigraphy using thallium-201 and positron emission tomography with metabolic imaging of myocardial glucose metabolism, using fluorine-18 fluoro-deoxyglucose, are today the most widely used nuclear methods for the assessment of myocardial viability. Besides the prediction of reversible regional and global myocardial dysfunction following coronary revascularization, both methods have demonstrated the ability to identify patient subgroups who will benefit most with regard to cardiac prognosis and survival and those patients in whom coronary revascularization has a limited effect with regard to survival and cardiac events. This short review summarizes the clinical impact of both imaging modalities on today's diagnostic approach in patients with ischemic left ventricular dysfunction.