Painless Myocardial Infarction Research Articles

Painless myocardial infarction - a clinical challenge in the emergency department.

Painless myocardial infarction - a clinical challenge in the emergency department.

Left ventricular thrombus and systemic embolism after painless myocardial infarction in a young female

Oral contraceptives are widely used because of their reliability. Although oral contraceptives are known to increase the risk of thromboembolic events, there are extremely few reports of oral contraceptive–induced left ventricular thrombus. Herein, we report a 37-year-old non-smoking female, who had regularly taken oral contraceptives for 14 years, developed an anterior myocardial infarction concomitant with left ventricular thrombus, bilateral segmental renal infarctions, and lower limb ischemia. Medical treatment with a combination of dual antiplatelet therapy and anticoagulants completely relieved her symptoms.

Approach to diabetic neuropathy

Neuropathy is the most common symptomatic complication of diabetes mellitus (DM) and accounts for a large share of morbidity and hospitalization associated with the disease. The symptoms of neuropathy in diabetes may present with somatic, autonomic, motor or sensory symptoms. Symmetric distal sensory polyneuropathy is the most common form, affecting the distal lower extremities and hands in a “glove and stocking” pattern. Cardiac autonomic neuropathy can, in particular, contribute to 6% of sudden deaths (painless myocardial infarction) among those with long-standing diabetes. Neuropathy whether sensory, motor, or autonomic may lead to the formation of fissures or calluses which lead to ulceration. Tight glycemic control is the only strategy which has demonstrated to show prevention and progress of diabetic peripheral neuropathy and autonomic neuropathy. Early treatment of diabetic neuropathy should, therefore, include tight glycemic control. All patients should be screened for diabetic neuropathy starting at diagnosis of type 2 DM and 5 years after diagnosis of type 1 DM and at least annually thereafter. An annual comprehensive foot examination is a must for all patients with diabetes and consists of examination of foot and footwear, neuropathy screening, vascular assessment, and musculoskeletal assessment of feet. This would help in identification of risk factor predictive of ulcers and amputation.

ATYPICAL CLINICAL COURSE OF THE ACUTE MYOCARDIAL INFARCTION: CLINICAL AND ANAMNESTIC CHARACTERISTIC OF PATIENTS, MANAGEMENT AND OUTCOMES (DATA FROM REGISTRY OF ACUTE MYOCARDIAL INFARCTION)

Aim. To study  clinical and  anamnestic   specifics,  management and outcomes  of acute  myocardial infarction (MI) in patients  with atypical clinical presentation. Material and methods. Among the Tomsk population, those  having had acute MI in 2009-2014 y. were included, registered  in the database “Registry of Acute MI” (n=5602), and selected  to groups with atypical (n=1319) and common (n=4283) clinical presentation  of the MI onset. Statistics was done with software “Statistica 10”. Results. Atypical presentation  of MI took place in 23,5% cases. These patients were much older than those with common angina at MI onset; they had more prevalent arterial hypertension,  obesity, diabetes.  Also, the prevalence of anamnestic MI did not differ between groups, however autopsy revealed more common painless MI. Atypical  MI presentation patients sought for medical care in 28 days before the event of MI more frequently than those with typical clinical picture: 36% vs. 26% (p<0,001), but electrocardiography  was ordered only for a half of them (54%), that led to misdiagnostics of pre-infarction condition. Every second  patient with atypical MI was hospitalized to non-specialized  unit, where could not  receive  high-technology  treatment,   which hence  led  to  worse outcomes and prognosis. Conclusion. It is necessary to be careful with non-typical MI development possibility in  older  patients   with several  comorbidities,  and  with anamnesis of painless acute MI. Chance of fatal outcome in atypical MI is  10  times  higher  in this  group  than  in those  with typical clinical presentation.

DISORDERS OF THE AUTONOMIC NERVOUS SYSTEM IN THE CARDIOLOGY PRACTICE: FOCUS ON THE ANALYSIS OF HEART RATE VARIABILITY

Heart rate variability (HRV) in patients with ischemic heart disease, a life-threatening heart rhythm disorders, as well as diabetes mellitus (DM) is considered. A significant association between the autonomic regulation of the cardiovascular system and death from cardiovascular causes is identified. The reactions of the autonomic nervous system (ANS) can serve as a precipitating factor of arrhythmias in patients with heart disorders. Analysis of HRV at rest is the main and informative method for determination of the ANS disorders. HRV decreases greatly in patients with acute myocardial infarction, cardiac arrhythmia, and DM, predicting a high risk of death. The leading cause of death in diabetic patients is cardiac autonomic neuropathy, with the development of silent ischemia and painless myocardial infarction. Autonomic regulation of the heart rate should be assessed for early diagnosis and prevention of complications in the form of sudden death.

A CASE OF PAINLESS MYOCARDIAL INFARCTION DUE TO BRIDGING OF LEFT ANTERIOR DESCENDING ARTERY

Myocardial bridging (MB) is congenital abnormality of the coronary arteries, which typically does not interfere with long term prognosis, but in some cases can cause myocardial infarction and other life-threatening conditions. This article reviews current knowledge about the anatomy, pathophysiology, clinical relevance, and treatment of MB and demonstrates a case of painless myocardial infarction in patients with MB of the left anterior descending artery.

Comparative analysis of clinical, electrocardiographic, angiographic and echocardiographic data of indigenous and non-indigenous residents of Yakutia with coronary artery atherosclerosis

AimThe aim of the study is to compare clinical, angiographic, electrocardiographic, echocardiographic data between indigenous and non-indigenous residents of Yakutia.Study designWe performed cross-sectional analysis of the Registry of Selective Coronary Angiography (SCAG) of the Yakutsk Republican Hospital for the period from 2004 to 2007. All patients (n=1,233) were admitted to hospital from all 35 regions of the Sakha Republic (Yakutia). Initially, 12 (1%) patients, who had abnormal coronary arteries and 259 (21%) patients with normal coronary arteries were excluded from this study. From the remaining 962 (78%) patients with detected coronary artery atherosclerosis 394 (41%) patients were excluded for having congenital heart malformations due to possible influence on the outcomes of examination for myocardial hypertrophy. Finally, only 568 patients were selected for further examinations.MethodsWe analyzed clinical data, and the findings of selective angiography, multi-detector computed tomography (CT), electrocardiography (ECG), 24-hour Holter ECG monitoring and echocardiography.Results(a) In the Sakha Republic (Yakutia) single-vessel coronary disease, coronary stenosis with 50–75% and 75–90% of constriction were detected more often among indigenous males, while multiple-vessel coronary stenosis was detected more often among non-indigenous males as well as stenosis with more than 90% of constriction. Lower calcium score mean (349.1±129.8 vs. 621.8±115.2) was observed among indigenous patients compared to non-indigenous patients; (b) Painless myocardial infarction, painless ischaemia, arterial hypertension and atrial fibrillation were detected more often among indigenous male compared to non-indigenous participants; (c) Based on the results of ECG and echocardiographic examinations, left ventricular (LV) hypertrophy, particular eccentric type of hypertrophy, was found more commonly among indigenous than non-indigenous males; and (d) By laboratory findings, indigenous males had significantly lower triglyceride levels, while platelet counts were higher compared to non-indigenous patients. Obesity was observed less frequently among indigenous men compared to non-indigenous men.ConclusionThe differences observed in this study are disputable and call for further studies. Collection of reliable data for women should be the aim of future studies.

UROGENITAL FORM OF DIABETIC AUTONOMOUS NEUROPATHIES: PREVALENCE, ETIOPATHOGENESIS, DIAGNOSTICS

Diabetic neuropathy (DN) is the most frequent complication of diabetes mellitus (DM), one of the leading causes of a decrease in the quality of life of patients, the development of fatal cardiac arrhythmias, painless myocardial infarction, renal failure, and disabling amputations. Diabetic neuropathy is a dysfunction of the somatic (autonomic) and / or peripheral nervous system caused directly by specific diabetic pathophysiological and dysmetabolic processes

Renal dysfunction as a risk factor for painless myocardial infarction: results from Korea Acute Myocardial Infarction Registry

Renal dysfunction has been associated with many types of neuropathy and the incidence of myocardial infarction (MI) presenting without chest pain can be expected to be higher in patients with renal dysfunction. We evaluated clinical outcomes of painless MI patients and relationship between renal dysfunction and painless MI. Study population consisted of 9,735 patients (63±13years, men 70.7%), whose discharge diagnosis by cardiac enzyme and electrocardiogram was MI. The study subjects were divided into two groups according to presence of chest pain (painful MI group, n=8,249; painless MI group, n=1486). Rates of in-hospital death, 1-month and 12-month composite MACE, cardiac death, and non-cardiac death were significantly higher in painless MI patients. In a multivariate logistic analysis, compared with glomerular filtration rate (GFR)>90mL/min/1.73m(2), odds ratio of painless MI was increased proportionally in patients with GFR of 30-59, 15-29 and <15mL/min/1.73m(2) (odds ratio [OR] 1.25, 95% confidence interval [CI] 1.05-1.49; OR 1.88, CI 1.39-2.53; OR 2.32, CI 1.65-3.26) In addition, the concomitant presence of renal dysfunction and diabetes mellitus significantly affected the prevalence of painless MI. Poorer outcomes of painless MI patients and the increased probability of painless MI proportional to declining GFR indicate that the possibility of painless MI should be considered in patients with renal dysfunction, particularly concomitant with diabetes mellitus.

Elevated soluble CD40 ligand in diabetic patients with painless myocardial infarction

Because a useful biomarker for painless myocardial infarction (MI) has yet to be identified, the aim of this study was to identify a biomarker for diabetic patients with painless MI. A case-control design was used to compare inflammatory cytokine levels among 111 patients with diabetes mellitus, including 31 patients with stable coronary heart disease (CHD), 30 patients with painful MI, 20 patients with painless MI, and 30 age- and sex-matched patients without CHD (control group). In addition to baseline parameters, cytokine levels, including plasma high sensitivity C-reactive protein (HsCRP), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and soluble CD40 ligand (sCD40L) levels, were analyzed using enzyme-linked immunosorbent assays (ELISAs). No differences in baseline characteristics were observed for patients with painless MI as compared to the other patient groups. Significantly higher sCD40L, HsCRP, IL-6, and TNF-α levels were detected in patients with MI, and markedly elevated sCD40L and IL-6 levels were observed in patients with painless MI as compared to those with painful MI. sCD40L may be a useful biomarker for painless MI in diabetic patients, which could reduce misdiagnosis and expedite treatment. Further studies are required to validate the diagnostic utility of this putative biomarker as well as investigate the mechanism by which sCD40L is elevated in these patients.

Cardiovascular autonomic neuropathy in spontaneously diabetic rats with and without application of EGb 761.

Cardiovascular autonomic neuropathy causes abnormalities in the diabetic heart with various clinical sequelae, including exercise intolerance, arrhythmias and painless myocardial infarction. Little is known about (ultra)structural alterations of the myocardial nervous network. On the assumption that this diabetes-specific neuropathy develops due to permanently increased oxidative stress by liberation of oxygen-free radicals, adjuvant application of antioxidative therapeutics appears promising in preventing or delaying long-term diabetic complications. We have investigated the effects of Ginkgo biloba extract (EGb 761), a radical scavenger, against diabetes-induced myocardial nervous damage in spontaneously diabetic BioBreeding/Ottawa Karlsburg (BB/OK) rats. Morphological and morphometric parameters were evaluated by electron microscopy. We used immunohistochemistry to investigate protein expression of protein gene product 9.5, S100 protein, and thyroxin hydroxylase as a neuronal marker. Alterations of cardiac sympathetic activity were measured using the in vivo 123I-metaiodobenzyl-guanidine imaging, and the immunofluorescent labeling of beta1-adrenergic receptors and adenylate cyclase. Our results revealed that A) Diabetes results in slight to moderate ultrastructural alterations (hydrops, disintegration of substructure) of autonomic nerve fibers and related Schwann cells in untreated BB diabetic rats; B) Cardiac sympathetic integrity and activity is impaired due to alterations in the presynaptic nerve terminals and the postsynaptic ß1-AR-AC coupling system; C) Pre-treatment of diabetic myocardium with EGb results in an improvement of most of these parameters compared to unprotected myocardium. In conclusion, EGb may act as a potent therapeutic adjuvant in diabetics with respect to cardiovascular autonomic neuropathy, which may contribute to the prevention of late complications in diabetes.

Diabetic rats show reduced cardiac–somatic reflex evoked by intrapericardial capsaicin

Painless myocardial infarction is a serious complication of diabetes. The present study examined whether cardiac nociception was altered in the streptozotocin-induced diabetic rat model by assessing intrapericardial capsaicin-evoked electromyography (EMG) responses in the spinotrapezius muscle. Somatic sensitivities to mechanical and thermal stimulation of the skin were also determined. Intrapericardial administration of capsaicin evoked a concentration-dependent EMG response, which was reproducible with repeated administration. However, the capsaicin-induced EMG responses were different in streptozotocin-induced diabetic rats and controls. Intrapericardial capsaicin produced fewer EMG responses, which were delayed and reduced in streptozotocin-treated rats compared to controls. Pretreatment with capsazepine, a TRPV1 antagonist, significantly decreased capsaicin-evoked EMG activity in both streptozotocin-treated and control rats. In addition, streptozotocin-treated rats showed a decreased paw withdrawal threshold in response to mechanical stimulation but no change in response to radiant heat stimulation. These results suggest that streptozotocin-induced diabetic rats develop somatic mechanical hypersensitivity (allodynia), but reduced cardiac nociception. Decreased TRPV1 function may contribute to the reduction of cardiac nociception in the diabetic rat.

Clinical Features of Patients with a Myocardial Infarction During Acute Management of an Ischemic Stroke

Ischemic stroke and myocardial infarction (MI) share some common risk factors and pathophysiological mechanisms. In addition, brain injury has been associated with abnormalities of heart function such as increased cardiac enzymes and EKG changes. However, there is little information on patients with post-stroke MI. In this study, we investigated the characteristics of ischemic stroke patients who had a MI during the acute stroke period. One thousand three hundred fifty-seven patients with acute ischemic stroke were studied by retrospective review of the stroke registry and inpatient charts. Among these patients, 12 that developed a post-stroke MI, during acute stroke management, were included in this study. The stroke subtype, pattern of arterial stenosis, and lesional dominance were analyzed. The overall frequency of a post-stroke MI during hospitalization was 0.9% (12 of 1,357 patients initially studied). Eight of the 12 patients included had a painless MI. Significant intracranial arterial stenosis was observed in 10 patients (83%). According to the TOAST classification, seven patients (58.3%) had large artery atherosclerosis, three patients were classified as undetermined etiology and two patients were divided into the lacunar and cardioembolic group. Acute ischemia of the insular region was noted in six patients. Five patients died from their cardiac complications during the hospital stay. Post-stroke MI can be a potential complication of acute ischemic stroke; these events have a high mortality. Routine EKG monitoring, during the acute stroke period, may improve patient outcome due to the possibility of a painless post-stroke MI.

Accident coronarien aigu révélé par un œdème pulmonaire survenu en plongée sous-marine

We report the case of a 64-year-old healthy male diver who presented an unusual diving-related pulmonary edema induced by a painless myocardial infarction with normal coronary arteriography. We review the related literature and discuss the pathophysiologic mechanisms that would contribute to provoke this myocardial injury during diving.

Clinical and experimental pain perception is attenuated in patients with painless myocardial infarction

Background. The lack of pain alarm in painless myocardial infarction (MI) leads to increased morbidity and mortality, since patients do not seek medical treatment in a timely manner. We aimed to explore whether reduced systemic pain perception in response to experimental stimuli and pain related personality variables characterizes painless MI patients. Methods. Level of chest pain intensity was assessed by numerical scale, range from 0 (no pain) to 100 (maximal pain). Heat pain threshold, magnitude estimation of supra-threshold phasic and tonic painful stimuli as well as anxiety and pain catastrophizing scores were assessed in 92 acute MI patients; 67 with and 25 without chest pain, respectively. All experimental stimuli were performed by Thermal Sensory Analysis (TSA) and applied to the right forearm. Results. Greater intensity of chest pain scores was inversely correlated with lower pain threshold (r=−0.417, p<0.001), and directly associated with higher pain scores in response to the heat pain (r=0.354, p=0.002). Patients with painful MI demonstrated lower pain threshold (41.9±3.6°C vs. 44.9±3.8°C, p=0.001) and higher catastrophizing level (10.6±12.0 vs. 5.4±8.8, p=0.032). Logistic regression analysis revealed that older age and lower pain scores in response to supra-threshold painful stimuli were associated with greater risk for painless MI. The demographic variables, history of ischemic heart, risk factors for coronary artery disease, ST-T segment changes on ECG and troponin levels were similar in both groups. Conclusions. This study suggests that reduced systemic pain perception as well as cognitive personality variables play an important role in the etiology of painless MI.

Renal Insufficiency is Related to Painless Myocardial Infarction

Acute myocardial infarction (MI) sometimes occurs without painful symptoms and in such cases, prognosis is worsened by delays in diagnosis and revascularization. Renal insufficiency induces many types of neuropathy, but the relation between renal insufficiency and painless MI remains unclear. Patients with MI and elevated creatine kinase levels were retrospectively analyzed. Renal insufficiency (serum creatinine concentration > or =1.5 mg/dl) and other characteristics (age, sex, body mass index, hypertension, smoking, diabetes mellitus, dyslipidemia, history of stroke, previous MI, hemodialysis, and atrial fibrillation) were compared between patients who had MI with painful symptoms (painful MI, n=131) and patients who had MI without painful symptoms (painless MI, n=18). Other variables compared were the time from symptom onset to admission, peak creatine kinase concentration, Killip class, site of MI, emergency coronary angiography, postprocedural Thrombolysis In Myocardial Infarction grade III flow, and in-hospital death. Univariate analysis identified older age, renal insufficiency, and previous MI as predictors of painless MI. Patients with painless MI showed higher rates of Killip class > or =II and in-hospital death and a longer time from symptom onset to admission. However, multivariate analysis identified only renal insufficiency as an independent predictor of painless MI. MI without painful symptoms frequently develops in patients who have renal insufficiency, so the possibility of painless MI should be evaluated in such patients to ensure early diagnosis and treatment.

Clinical consequences of cardiovascular autonomic neuropathy in diabetic patients.

A wide range of clinical consequences of cardiovascular autonomic neuropathy (CAN) can be observed in diabetic patients and contributes to the clinical picture of the diabetic heart. Resting heart rate and cardiovascular reflexes as well as circadian heart rate variability may be altered by CAN in diabetes. Moreover, blood pressure is also influenced by sympathovagal imbalance. Postural hypotension is a clinical characteristic in diabetic subjects with CAN. Painless myocardial infarction, ischaemia and left ventricular dysfunction are also observed in some cases. Impairment of cardiac parasympathetic and sympathetic innervation as well as QT-interval prolongation may play a partial role in the pathogenic mechanism of sudden unexpected death in diabetic patients. The risk of surgical intervention and that of anaesthesia are increased due to abnormal cardiovascular reactions. Clinical symptoms and signs of CAN should be assessed as severe diabetic complication and the therapy is difficult in some cases. Taken together, symptoms and signs of CAN carry a poor prognosis in diabetic patients.

Vascular complications of diabetes mellitus.

1. Macro- and microvascular diseases are the main chronic complications of diabetes mellitus (DM). 2. It has been shown that DM patients have more severe nailfold microcirculatory disturbances than patients with liver cirrhosis or systemic lupus erythematosus (SLE). 3. It has been shown that the glomerular basement membrane of diabetic rats is significantly thickened compared with that of normal rats (295.5 +/- 45.1 vs 184.8 +/- 33.2 nm). 4. Gastric mucosal blood flow (GMBF) in 41 patients with non-insulin-dependent diabetes mellitus (NIDDM) was determined with a laser Doppler flowmeter. The results showed that average GMBF values at 14 sites in the gastric mucosa were significantly lower in NIDDM patients than in control subjects. 5. The percentage of painless acute myocardial infarction (AMI) among 50 patients with DM was 22.0% and the mortality of AMI was 22.0% (11 cases). Both these values were higher than the corresponding values in patients without DM (9.9 and 11.4%, respectively; P < 0.05). 6. Cerebrovascular disease is more prevalent in diabetic patients than in non-diabetics and the mortality of stroke in DM patients is two-fold higher than that of non-diabetic patients. 7. Diabetes can result in widespread macrovascular atherosclerosis and microcirculatory disorders of multiple organs.

A critical analysis of the concept of silent myocardial ischaemia.

It has been known for many years that myocardial ischaemia can be either painful or totally painless. In Prognostic interest the latter case it is often called silent ischaemia. However, this term is inaccurate because the absence The interest in detecting silent ischaemia is also a of pain does not imply that there are no consequences. matter of debate. It is generally accepted that in Silent ischaemia in reality can be observed with stable identified coronary heart disease patients, the associor unstable angina, and even with myocardial infarc- ation of painless ischaemia with symptomatic ischaemic tion, and can be severe, complicated by left ventricular episodes implies a greater pejorative prognosis. It could failure, arrhythmia or even sudden death. The term be the harbinger of more serious events (infarction, painless ischaemia would be more appropriate. Peter sudden death) or gradually induce irreversible Cohn, a leading expert in the field, proposed the myocardial damage. In contrast, the prognostic signidistinction of three types of patients with painless ficance of strictly isolated painless myocardial ischmyocardial ischaemia [1]: type I patients are rigorously aemia (i.e. not associated with painful ischaemia) is and totally asymptomatic. This type is thought to highly variable and very deeply influenced by suscepticoncern 2.5‐10% of middle-aged men. The scope there- bility: in identified coronary heart disease patients it fore is wide. Type II would involve patients undergoing aggravates prognosis; in patients showing no clinical asymptomatic electrical ischaemia during exercise after or para-clinical signs of coronary disease, its prognostic myocardial infarction. It is estimated that one-fifth of weight may be nil. Lastly, regardless of the prognostic patients recovering from myocardial infarction have significance of painless ischaemia, there is no proof such asymptomatic ECG episodes. Lastly, type III that its prevention by anti-angina medication may involves patients where angina is associated with epis- improve prognosis. odes of asymptomatic myocardial ischaemia, and is thought to apply to 40‐50% of treated coronary heart disease patients. These figures reflect the very high Diagnostic methods frequency of painless myocardial infarction and underline the necessity of assessing its prognostic impact Detecting silent ischaemia requires additional examinaand/or the optimal diagnostic and therapeutical tion and tests, the first being electrocardiographic methods. ( ECG, exercise test, Holter), but also including perfusion scintigraphy, stress echography, myocardial contrast echocardiography or even exploration of The pathophysiology myocardial metabolism by positron emission tomography. These tests are usually validated by comparThe reasons why myocardial ischaemia is painless are ison with coronary angiography. Nevertheless, the yet to be elucidated. Several clinical data suggest that latter technique only provides information on the these ischaemias are usually less severe or shorter than anatomy of coronary lesions and does not evaluate symptomatic episodes. There are grounds also for ischaemia. By far the most widely used test in practice considering the possibility that nociceptive perception is Holter ECG. This test, an extremely valuable one abnormalities may exist in patients with asymptomatic for monitoring rhythm disorders, has major limitations myocardial ischaemia. The role of the endorphinic with regard to the detection and surveillance of myocardial ischaemia. Its main limitation is its lack of specificity. When applying Bayesian analytical rules to the diagnostic performance of a test, its positive and

Lack of pain during myocardial infarction in diabetics —Is autonomic dysfunction responsible?

Coronary artery disease is the most frequent cause of death among adult diabetic patients. 1 Myocardial ischemia is often silent in these patients, 2 and 33 to 42% of them do not experience chest pain during myocardial infarction. 3 Absence of pain has been attributed to autonomic neuropathy, 3–5 which is fairly common in patients with diabetes. Silent myocardial ischemia, 2 infarction 4–6 and sudden cardiac death 6,7 occur most often in patients who also have autonomic dysfunction. Diabetic patients dying of painless myocardial infarction have morphologic features typical of diabetic neuropathy in the autonomic nerve fibers supplying the heart. 4 However, not all patients with florid diabetic autonomic neuropathy have painless myocardial infarction. 5 The mechanism of painless myocardial infarction in diabetic patients, therefore, remains unclear and it is not known whether autonomic dysfunction is responsible for the lack of pain. No systematic study has examined the differences in autonomic functions between diabetic patients with painful and painless myocardial infarctions. Therefore, this study investigated the autonomic functions in 14 diabetic patients with myocardial infarction, 7 of whom had no chest pain during infarction.