Episodes Of Recurrent Ischemia Research Articles

Microvascular Dysfunction in Hypertrophic Cardiomyopathy.

Myocardial ischemia is an established pathophysiological feature of hypertrophic cardiomyopathy (HCM) that impacts various clinical features, including heart failure (HF) and sudden cardiac death (SCD). The major determinant of myocardial ischemia in HCM is coronary microvascular dysfunction (CMD) in the absence of epicardial coronary artery abnormalities. Despite the impossibility to directly visualize microcirculation in vivo, a multimodality approach can allow a detailed assessment of microvascular dysfunction and ischemia. Accordingly, the non-invasive assessment of CMD using transthoracic Doppler echocardiography, positron emission tomography, and cardiac magnetic resonance should now be considered mandatory in any HCM patient. Noteworthy, a complete diagnostic work-up for myocardial ischemia plays a major role in the approach of the patients with HCM and their risk stratification. Chronic and recurrent episodes of ischemia can contribute to fibrosis, culminating in LV remodeling and HF. Ischemia can potentially constitute an arrhythmic substrate and might prove to have an added value in risk stratification for SCD. Accordingly, strategies for the early diagnosis of CMD should now be considered an important challenge for the scientific community.

ОСОБЕННОСТИ НАРУШЕНИЙ СЕРДЕЧНОГО РИТМА И ПРОВОДИМОСТИ ПРИ ИНФАРКТЕ МИОКАРДА С РЕЦИДИВИРУЮЩИМИ ЭПИЗОДАМИ ИШЕМИИ У МУЖЧИН МОЛОЖЕ 60 ЛЕТ

Relevance. Heart arrhythmia in early postinfarction angina and recurrent myocardial infarction is negatively affected the prognosis of the disease. Aim. To evaluate the peculiarities of heart rhythm and conduction disturbances and electrocardiographic (ECG) changes in men under 60 years old with early postinfarction angina and recurrent myocardial infarction for improve prevention and outcomes. Material and methods. The study included men aged 19-60 years old with myocardial infarction type I. Patients were divided into two age-comparable groups: I - study group with recurrent episodes of ischemia (early postinfarction angina pectoris and / or recurrent MI) - 110 patients; II - control, without them - 555 patients. A comparative assessment of heart arrhythmias and electrocardiographic changes observation frequency in the selected groups was performed. Results. In the patients of the study group more often than among all other patients, ventricular fibrillation was observed (8.5 and 3.9%, respectively; p = 0.04), paroxysmal supraventricular tachycardia (5.7 and 1.8%; p = 0.02) and electrocardiographic signs of the right atrium enlargement (9.4 and 1.6%; p ˂ 0.0001). In group I, among the deceased, electrocardiographic signs of left ventricular hypertrophy were more often detected (93.3 and 57.9%; p = 0.02). Arrhythmias that started in the subacute period of myocardial infarction were recorded with the same frequency in both groups of patients (1.4 and 1.6%; p = 0.9). Conclusions. Men under 60 years old with recurrent episodes of ischemia in myocardial infarction are characterized by potentially curable ventricular fibrillation and supraventricular tachycardias. Electrocardiographic signs of left ventricular enlargement were an additional marker of a poor prognosis for these patients. The frequency of occurrence of "late" arrhythmias in this pathology is 1.4%, and the methods of their possible correction require clarification depending on the mechanism of their development.

СОСТОЯНИЕ ЛИПИДНОГО ОБМЕНА У МУЖЧИН МОЛОДОГО И СРЕДНЕГО ВОЗРАСТА С ИНФАРКТОМ МИОКАРДА И РЕЦИДИВИРУЮЩИМИ ЭПИЗОДАМИ ИШЕМИИ

Relevance. Dyslipidemia is considered one of the main risk factors for the development of recurrent myocardial infarction and early postinfarction angina. Aim. To evaluate the features of lipid metabolism in acute and subacute myocardial infarction in men under 60 years old with recurrent episodes of ischemia (recurrent myocardial infarction and/or early postinfarction angina) to search for new approaches to improve prevention measures. Material and methods. The study included men aged 19-60 years old with type I myocardial infarction. Patients are divided into two age-comparable groups: I - the study group, with recurrent myocardial infarction - 68 patients; II - control, without it - 427 patients. A comparative assessment of lipid metabolism parameters and their dynamics in selected groups were performed. Results. The study group differed in higher levels of total serum cholesterol (6.17±1.78 mmol/l) from the control group (5.56±1.28 mmol/l; p=0.02) at the end of the third week of disease, its dynamics during the observation period (I: 9.1%; p<0.0001; II: -1.8%; p<0.0001) and the dynamics of the atherogenic coefficient (I: -4.7.1; p=0.02; II: 6.3%; p<0.0001). In both groups, the group showed an increase in lipoproteins of low (I: 33.1; p=0.02; II: 45.5%; p<0.0001) and very low density (I: 275.8; p=0,0004; II: 233.4%; p<0.0001), atherogenic indices, decrease: triglycerides (I: -31.8%; p=0.02; II: -1.7%; p<0.0001) and high-density lipoproteins (I: -0.6%; p=0.02; II: -6.1%; p<0.0001). Conclusions. The group with recurrent ischemia is characterized by more pronounced hypercholesterolemia at the end of the subacute period of myocardial infarction in comparison with the control group due to an increase in the concentrations of atherogenic lipid metabolism fractions. The dynamics of indices and the coefficient of atherogenicity during this period is multidirectional, which requires additional study.

ELECTROLYTIC EXCHANGE FEATURES DURING MYOCARDIAL INFARCTION WITH RECURRENT EPISODES OF ISCHEMIA IN MEN UNDER 60 YEARS OLD

Relevance. Recurrent myocardial infarction and early postinfarction angina negatively effects on the prognosis of myocardial infarction. Aim. To evaluate myocardial infarction sodium, potassium, chlorides, calcium metabolism, features in men under 60 years old with recurrent myocardial infarction and early postinfarction angina to improve prevention and outcomes. Material and methods. The study included men aged 19-60 years old with type I myocardial infarction. Patients are divided into two age-comparable groups: I - the study group, with recurrent myocardial infarction - 110 patients; II - control, without it - 555 patients. A comparative analysis of blood serum electrolyte levels, their dynamics from the first hours to the end of the third week of myocardial infarction in the selected groups were performed. Their impact on the risk of recurrent ischemia and unfavorable outcome was assessed. Results. In the study group, in the first hours of the disease, the levels of chloride were higher (103.7±5.5 and 101.7±4.7 (mmol/l); p=0.002), and total calcium at the end of the third week of myocardial infarction (2.3±0.2 mmol/l) - lower than in the control (2.46±0.16; p=0.001). With an unfavorable outcome in the study group, the sodium level was lower in the first hours of the disease (138.7±4.9 and 142.7±6.6 (mmol/l); p=0.049). Moreover, the risk of its development was associated with sodium levels ≥148.0 mmol/l (absolute risk: 100.0%; relative - 13.8; p<0.0001) and potassium levels ≥5.3 mmol/l (absolute: 71,4%; relative - 12.4; p<0.0001). The risk of developing recurrent episodes of ischemia in the examined increased at chloride levels ≥104.7 mmol/l (absolute: 28.4%; relative: 3.1; p=0.0001) and sodium ≥139.0 mmol/l (absolute: 19.5%; relative: 1.7; p=0.03) in the first hours of myocardial infarction and calcium (<2.4 mmol/l) at the end of the third week of the disease (absolute: 31.0%; relative: 4.9; p=0.003). Conclusions. The listed combinations of levels of basic electrolytes in blood serum are markers of recurrence of ischemia in myocardial infarction and poor outcome. They should be used to identify risk groups with the necessary preventive measures and for predictive modeling.

Impairment of microcirculation and vascular responsiveness in adolescents with primary Raynaud phenomenon

Background Raynaud’s phenomenon (RP) is a functional vascular disease, presenting with recurrent episodes of ischemia of extremities in response to cold and emotional stress. Investigating cutaneous microcirculation is an important tool in understanding the complex neuro-immuno-vascular interactions in its pathophysiological mechanisms. Since there is no available data on vascular responsiveness in RP in the paediatric population, we investigated skin perfusion and heat-induced hyperaemia in comparison with clinical severity and laboratory parameters of the disease.MethodsFifty two adolescents (27 patients with primary RP and 25 age-matched healthy controls) were investigated in the study. Patients were divided into two groups according to the symptoms existing within the previous 2 months. Following baseline microcirculation measurement with Laser Doppler flowmetry (Periflux 5000 system), all subjects underwent local heating test at 42 °C and 44 °C. Besides routine laboratory parameters, immune-serological tests and the vasoactive sensory neuropeptides somatostatin and pituitary adenylate-cyclase activating polypeptide (PACAP) were measured.ResultsBaseline perfusion measured in perfusion units (PU) at 32 °C was significantly lower in symptomatic RP patients (97.6 ± 22.4 PU) compared with both healthy volunteers (248.3 ± 23.5 PU, p < 0.001) and RP patients without symptoms (187.4 ± 24.9 PU, p < 0.05). After local heating to 42 °C maximum blood flow was significantly reduced in primary RP participants with current symptoms (358.6 ± 43.9 PU, p < 0.001), but not in asymptomatic ones (482.3 ± 28.7 PU, p > 0.05) when compared with healthy subjects (555.9 ± 28.2 PU). Both the area under the response curve and the latency to reach the maximum flow were significantly increased in both RP groups (symptomatic 164.6 ± 7.4 s, p < 0.001, asymptomatic 236.4 ± 17.4 s, p < 0.001) when compared with the control group (101.9 ± 4.7 s). The heat-induced percentage increase from baseline to maximal blood flow was significantly greater in symptomatic RP adolescents in comparison with healthy ones. Laboratory parameters and neuropeptide plasma levels were not altered in any groups.ConclusionTo our knowledge this is the first study in paediatric population to show altered heat-induced cutaneous hyperaemia responses in relation with the clinical severity and symptomatology.

AHA/ACCF Scientific Statement on the Evaluation of Syncope

AHA/ACCF Scientific Statement on the Evaluation of Syncope

Outcome of catheter-directed thrombolysis for lower extremity arterial bypass occlusion.

The purpose of this study was to determine the clinical outcome of patients undergoing catheter-directed thrombolysis (CDT) for lower extremity arterial bypass (LEAB) occlusion. A retrospective review was performed of two university-based practices from 1988 to 2001. All patients with LEAB occlusion (<14 days by history) undergoing CDT as initial treatment were included. Technical success, complications, secondary patency, and limb salvage were examined. Additional analysis examined secondary procedures performed for residual lesions or failed CDT and the number of LEABs that were replaced or that became infected. One hundred four patients (77% male; mean age, 65 years) had 109 LEAB occlusions. CDT restored patency in 77%. Of the 25 LEABs that failed initial CDT, 15 underwent surgical thrombectomy/revision, four were replaced, and six underwent no further interventions. Of the 84 LEABs successfully lysed, 51 had residual lesions that underwent revision with interventional (n = 30) or surgical (n = 15) techniques or both (n = 6). Median hospital stay was 8 days with three periprocedural deaths. One quarter of CDT procedures had bleeding or thrombotic complications or both. The mean follow-up period was 45 months. Secondary patency rates on an intention-to-treat basis (attempted thrombolysis) were 32% and 19% at 1 and 5 years, respectively. After successful CDT, the 1-year secondary patency rate was comparable in LEABs with or without residual lesions (42% versus 45%). Overall, the limb salvage rates were 73% and 55% at 1 and 5 years, respectively. The survival rate was 56% at 5 years. Ten of the 54 LEABs (19%) that eventually failed after successful CDT had three or more reocclusive episodes. Seven LEABs (8.3%) salvaged with CDT eventually became infected from recurrent interventions; six of these necessitated major amputation. Twenty LEABs initially salvaged with CDT were replaced (four immediately and 16 after episodes of recurrent ischemia). Two patients died during hospitalization for treatment of recurrent ischemia. Despite relatively high initial technical success for LEAB thrombolysis, eventual failure is the rule rather than the exception. Recurrent LEAB occlusions lead to significant morbidity, including recurrent interventions, eventual graft infection/replacement, and limb loss. However, LEAB replacement has substantial problems associated with limited conduit, reoperative anatomy, and subsequent wound complications. We therefore advocate an initial attempt at CDT with liberal use of graft replacement for early and late failures or as an initial strategy in those with favorable remaining conduit.

Recurrent ischemia during continuous 12-lead ECG-ischemia monitoring in patients with acute coronary syndromes treated with eptifibatide: Relation with death and myocardial infarction

Computer-assisted continuous monitoring of the ST-segment allows detection and quantification of recurrent ischemia in patients with acute coronary syndromes. In a substudy of the PURSUIT (Platelet glycoprotein IIb/IIIa in Unstable angina: Receptor Suppression Using Integrilin Therapy) trial, this technique was used to evaluate the effects of the glycoprotein IIb/IIIa inhibitor eptifibatide on the incidence and severity of recurrent ischemia, and to investigate the relationship between recurrent ischemia and the occurrence of subsequent death or myocardial (re)infarction. A total of 258 patients with unstable angina or evolving myocardial infarction without ST elevation were monitored for 24 hours during infusion with either eptifibatide or placebo with a computer-assisted 12-lead ECG-ischemia monitoring device. Recurrent ischemic episodes were identified by an automated computer algorithm. Two hundred and sixteen patients (84%) had ECG recordings suitable for analysis. Ischemic episodes were detected in 35 (33%) of the 105 eptifibatide patients and in 32 (29%) of the 111 placebo patients (not significant). No difference in ischemic burden was apparent between both treatment groups. Patients who exhibited 2 or more episodes of recurrent ischemia more frequently died or suffered a myocardial infarction, both at 7 and 30 days, as well as through the 6-month follow-up. A greater ischemic burden was significantly related to adverse outcome during the 6-month follow-up period. Real-time computer-assisted continuous multilead ECG-ischemia monitoring may help to identify patients with unstable coronary syndromes at increased risk of adverse outcome and, thus, allow for better prognostic triage and more appropriate selection of therapeutic strategies. Integration of these systems in coronary care units and emergency wards should, therefore, be recommended.

Patient recovery after infrainguinal bypass grafting for limb salvage

Purpose: The outcome of infrainguinal bypass surgery for limb salvage has traditionally been assessed by graft patency rates, limb salvage rates, and patient survival rates. Recently, functional outcome of limb salvage surgery has been assessed by patient ambulatory status and independent living status. These assessments fail to consider the adverse long-term patient effects of delayed wound healing, episodes of recurrent ischemia, and need for repeat operations. An ideal result of infrainguinal bypass surgery for limb salvage includes an uncomplicated operation, elimination of ischemia, prompt wound healing, and rapid return to premorbid functional status without recurrence or repeat surgery. The present study was performed to determine how often this ideal result is actually achieved. Methods: The records of 112 consecutive patients who underwent initial infrainguinal bypass surgery for limb salvage 5 to 7 years before the study were reviewed for operative complications, graft patency, limb salvage, survival, patient functional status, time to achieve wound healing, need for repeat operations, and recurrence of ischemia. Results: The mean patient age was 66 years. The mean postoperative follow-up was 42 months (range, 0 to 100.1 months). After operation 99 patients (88%) lived independently at home and 103 (92%) were ambulatory. There were seven perioperative deaths (6.3%), and wound complications occurred in 27 patients (24%). By life table, the assisted primary graft patency and limb salvage rates of the index extremity 5 years after operation were 77% and 87%, respectively, and the patient survival rate was 49%. At last follow-up or death, 73% of the patients (72 of 99) who lived independently at home before the operation were still living independently at home, and 70% (72 of 103) of those who were ambulatory before the operation remained ambulatory. Wound (operative and ischemic) healing required a mean of 4.2 months (range, 0.4 to 48 months), and 25 patients (22%) had not achieved complete wound healing at the time of last follow-up or death. Repeat operations to maintain graft patency, treat wound complications, or treat recurrent or contralateral ischemia were required in 61 patients (54%; mean, 1.6 reoperations/patient), and 26 patients (23.2%) ultimately required major limb amputation of the index or contralateral extremity. Only 16 of 112 patients (14.3%) achieved the ideal surgical result of an uncomplicated operation with long-term symptom relief, maintenance of functional status, and no recurrence or repeat operations. Conclusions: Most patients who undergo infrainguinal bypass surgery for limb salvage require ongoing treatment and have persistent or recurrent symptoms until their death. A significant minority have major tissue loss despite successful initial surgery. Clinically important palliation is frequently achieved by bypass surgery, but ideal results are distinctly infrequent. (J Vasc Surg 1998;27:256-66.)

Evidence for arterial embolization in dissecting aneurysm of the cervical vertebral artery

Ultrasonographic imaging of the right cervical vertebral artery in a 57-year-old man with recurrent episodes of ischemia in the vertebrobasilar territory revealed a dissecting aneurysm with communication of the true and false lumen. This finding demonstrates that arterial dissection can form a nidus for distal embolization and supports the use of anticoagulation in this disorder.

Dynamic Coronary Thrombosis: A Possible Cause of Prinzmetal's Variant Angina

Two patients presented with features typical of Prinzmetal's variant angina: recurrent episodes of chest discomfort at rest associated with transient ST segment elevation. Episodes of recurrent ischemia persisted despite treatment with intravenous nitroglycerin. Coronary arteriography disclosed a high grade stenotic lesion and intracoronary thrombus in both patients. Coronary spasm was not demonstrated. These observations suggest that “dynamic thrombosis” may have a more important role than heretofore recognized in some patients with Prinzmetal's variant angina.