Prinzmetal angina: ECG changes and clinical considerations: a consensus paper

Accidental Hypothermia-Induced J Wave Coupled With Giant R Wave Augmented by Premature Atrial Contraction: A Case Report

The 12-lead electrocardiographic findings in hypothermia include the presence of J waves; prolongation of the PR, QRS, and QT intervals; and atrial and ventricular dysrhythmias. Among these findings, the J wave, known as the Osborn wave, is considered pathognomonic. In 1953, the J wave was reported as a specific response to hypothermia in dogs, representing the current at the site of injury instead of a widening of the QRS complex that occurs caused by a conduction delay. The J wave is often accompanied by ventricular fibrillation. For the past 28 years, it was assumed that the hypothermia-induced J wave was mediated by the transient outward current. However, it was recently been reported that the J waves in some patients with hypothermia can be considered delayed conduction-related waveforms. Here, we present a case of hypothermia-induced J waves together with giant R waves, which have not been previously reported during hypothermia, augmented by short RR intervals arising from premature atrial contractions. Our observations indicate that the underlying mechanism for the genesis of J waves is indeed conduction delay and not transient outward currents.

Case report: Prinzmetal angina in adolescent

Prinzmetal angina is a rare condition more likely to be reported in adults. Vasospasm is by far notable for causing this condition. We present a case of Prinzmetal angina in a 17-year-old male who experienced unexplained resting chest pain for 2 days.

Cellular Mechanisms of Coronary Artery Spasm

Coronary artery spasm (CAS) is a reversible phenomenon caused by spontaneous excessive vascular smooth muscle contractility and vascular wall hypertonicity, which results in partial or complete closure of the lumen of normal or atherosclerotic coronary arteries. The clinical picture of CAS includes chest discomfort which is similar in quality to that of stable effort angina. Mechanisms underlying the development of CAS are still unclear. CAS certainly is a multifactorial disease. In this review, we paid attention to the role of the main pathophysiologic mechanisms in CAS: endothelial dysfunction, chronic inflammation, oxidative stress, smooth muscle hypercontractility, atherosclerosis and thrombosis, and mutations leading to deficient aldehyde dehydrogenase 2 (ALDH2) activity. These findings might shed novel insight on the underlying mechanisms and identify potential diagnostic and therapeutic targets for cardiovascular diseases in the future.

Coronary Vasospastic Angina: A Review of the Pathogenesis, Diagnosis, and Management

Vasospastic angina (VSA) is an under-appreciated cause of chest pain. It is characterised by transient vasoconstriction of the coronary arteries and plays a significant role in the pathogenesis of stable angina and acute coronary syndromes. Complex mechanistic pathways characterised by endothelial dysfunction and smooth muscle hypercontractility lead to a broad spectrum of clinical manifestations ranging from recurrent angina to fatal arrhythmias. Invasive provocation testing using intracoronary acetylcholine or ergonovine is considered the current gold standard for diagnosis, but there is a wide variation in protocols amongst different institutions. Conventional pharmacological therapy relies on calcium channel blockers and nitrates; however, refractory VSA has limited options. This review evaluates the pathophysiology, diagnostic challenges, and management strategies for VSA. We believe global efforts to standardise diagnostic and therapeutic guidelines will improve the outcomes for affected patients.

A Weighted Error Distance Metrics (WEDM) for Performance Evaluation on Multiple Change-Point (MCP) Detection in Synthetic Time Series

Change-point detection (CPD) is to find abrupt changes in time-series data. Various computational algorithms have been developed for CPD applications. To compare the different CPD models, many performance metrics have been introduced to evaluate the algorithms. Each of the previous evaluation methods measures the different aspects of the methods. Based on the existing weighted error distance (WED) method on single change-point (CP) detection, a novel WED metrics (WEDM) was proposed to evaluate the overall performance of a CPD model across not only repetitive tests on single CP detection, but also successive tests on multiple change-point (MCP) detection on synthetic time series under the random slide window (RSW) and fixed slide window (FSW) frameworks. In the proposed WEDM method, a concept of normalized error distance was introduced that allows comparisons of the distance between the estimated change-point (eCP) position and the target change point (tCP) in the synthetic time series. In the successive MCPs detection, the proposed WEDM method first divides the original time-series sample into a series of data segments in terms of the assigned tCPs set and then calculates a normalized error distance (NED) value for each segment. Next, our WEDM presents the frequency and WED distribution of the resultant eCPs from all data segments in the normalized positive-error distance (NPED) and the normalized negative-error distance (NNED) intervals in the same coordinates. Last, the mean WED (MWED) and MWTD (1-MWED) were obtained and then dealt with as important performance evaluation indexes. Based on the synthetic datasets in the Matlab platform, repetitive tests on single CP detection were executed by using different CPD models, including ternary search tree (TST), binary search tree (BST), Kolmogorov–Smirnov (KS) tests, t-tests (T), and singular spectrum analysis (SSA) algorithms. Meanwhile, successive tests on MCPs detection were implemented under the fixed slide window (FSW) and random slide window (RSW) frameworks. These CPD models mentioned above were evaluated in terms of our WED metrics, together with supplementary indexes for evaluating the convergence of different CPD models, including rates of hit, miss, error, and computing time, respectively. The experimental results showed the value of this WEDM method.

Acetylcholine Rechallenge: A First Step Toward Tailored Treatment in Patients With Coronary Artery Spasm

OBJECTIVES

The present study aimed to assess the feasibility and clinical value of acetylcholine (ACh) rechallenge for the detection of coexisting epicardial and microvascular spasm and to determine the efficacy of nitroglycerin in these spasm endotypes.

BACKGROUND

The coexistence of epicardial and microvascular spasm is difficult to identify; thus, its frequency is unknown. Nitroglycerin treatment is equally recommended for both epicardial and microvascular coronary spasm despite contradictory data.

METHODS

In this multicenter study, 95 patients with coronary spasm were included to undergo ACh rechallenge, which consisted of repeated ACh provocation 3 minutes after intracoronary nitroglycerin administration using the same dose that previously induced spasm.

RESULTS

In total, 95 patients (age 61 ± 12 years, 69% female) were included. Fifty-five patients (58%) had microvascular spasm, and 40 patients (42%) had epicardial spasm during initial ACh provocation. In 48% of patients with epicardial spasm, ACh rechallenge revealed coexisting nitroglycerin-persistent microvascular spasm. Nitroglycerin administration before ACh rechallenge prevented reinducibility of epicardial spasm in all patients with focal spasm and in 80% of patients with diffuse spasm. Microvascular spasm was prevented in only 20% by prior nitroglycerin administration but was attenuated in another 49% of patients.

CONCLUSIONS

This study demonstrates a high frequency of epicardial spasm with coexisting nitroglycerin-persistent microvascular spasm. Intracoronary nitroglycerin was very effective in preventing reinducibility of epicardial spasm, whereas it prevented microvascular spasm in only 20% of patients. ACh rechallenge is a novel method that facilitates the detection of coexisting spasm endotypes and may pave the way towards tailored treatment of vasospastic angina.

Coronary vasospasm as an etiology of recurrent ventricular fibrillation in the absence of coronary artery disease: a case report

Background: Vasospastic angina (VA), or Prinzmetal’s angina, is characterized by symptoms of coronary angina caused by coronary vasospasm, usually in the absence of atherosclerotic changes. It typically presents with chest pain, which can be accompanied by transient electrocardiographic changes, if visualized during the attack. It can also rarely present with severe manifestations of acute myocardial angina, ventricular fibrillation, or cardiac arrest.

Case presentation: We present a case of a 50-year-old Caucasian male who initially presented to the hospital with chest pain and was diagnosed with VA. Later, he was brought to the hospital by emergency medical services later with ventricular fibrillation, despite normal coronary anatomy on angiogram. He was managed with placement of an intra–cardiac defibrillator (ICD) for secondary prevention. The patient continued to have recurrent episodes of ventricular fibrillation with associated ICD shocks, and had multiple admissions to the hospital with similar presentations. Symptoms and arrhythmia improved after optimizing antianginal therapy.

Conclusions: Ventricular fibrillation can be an uncommon but severe manifestation during VA crises. In cases with normal coronary vasculature, it is important to recognize VA as a cause of recurrent ventricular fibrillation in order to optimize medical management for prevention of fatal arrhythmias.

Comparative analysis of ischemic changes in electrocardiogram and coronary angiography results: A retrospective study

To improve the correct diagnosis rate of coronary heart disease and to explore the guiding value of electrocardiogram (ECG) ST-T ischemic changes in the clinical diagnosis of coronary heart disease.A retrospective analysis was conducted on a total of 310 cases who underwent a conventional 12-lead ECG, 12-lead dynamic ECG (DECG, Holter) with ST-T ischemic changes, and then coronary angiography (CA) within 1 week in Qingdao Sttarr Heart Hospital from June 2015 to April 2020 in the study. Ischemic ST-T changes were evaluated using conventional diagnostic criteria, and Judkins diagnostic criteria were used in CA. The sensitivity and specificity of ECG were analyzed.The specificity of ST-T changes in conventional ECG for the diagnosis of coronary heart disease is 33.7% and the sensitivity is 66.0%. The specificity of ST-T changes in Holter in the diagnosis of coronary heart disease is 55.6% and the sensitivity is 32.2%. The sensitivity of conventional ECG for the diagnosis of coronary heart disease is better than Holter, but its specificity is inferior to Holter. The negative likelihood ratios of the 2 ECGs for the diagnosis of coronary heart disease were 1.0 and 1.22, both >0.1, and the positive likelihood ratios were 0.99 and 0.73, both <10. The positive results of ST-T in conventional ECG were 128 males (65.7%), 77 females (66.9%), (P < .05), 148 cases (74.7%) in the group ≥60 years old, and 75 cases in the group less than 60 years (67%), (P > .05). The positive results of ST-T change of DECG were 135 males (69.2%), 69 females (60.0%), (P < .05), 152 cases (78.7%) in the group ≥60 years, and 83 cases (70.9%) in the group less than 60 years, (P > .05). Coronary heart disease-related factors: symptoms, hypertension, diabetes, cancer, family history, smoking history as independent variables, and a binary multivariate logistic regression analysis was performed.The sensitivity of DECG in the diagnosis of myocardial ischemia in women and the elderly was slightly higher than that in men and young cases. ST-T ischemic changes in ECG are more significant for the diagnosis of coronary heart disease in male patients. Smoking, hypertension, diabetes, and family history are all high-risk factors for coronary heart disease.

Pathobiology and evolving therapies of coronary artery vasospasm

Coronary artery vasospasm is a known cause of chest pain and requires a high level of clinical suspicion for diagnosis. It also remains in the differential diagnosis for patients presenting with type 2 myocardial infarction. There are few randomized controlled trials for guideline-based prevention and treatment for coronary artery vasospasm. In this article, we review updated concepts in coronary artery vasospasm. Specifically, our aim is to provide current evidence of pathophysiology, identify the risk factors, propose a diagnostic algorithm, review available evidence of evolving therapies, and identify patients who would benefit from automatic implantable cardioverter defibrillators.

Variant Angina with Spontaneously Documented Ischemia- and Tachycardia-induced "Lambda" Waves

In a patient with variant angina of the proximal left anterior descending coronary artery, myocardial ischemia changed the QRS-ST-T configurations without J-waves into those resembling "lambda" waves at maximal ST-segment elevation, and couplets or triplets of supraventricular extrasystole (SVE) changed the ischemia-induced "lambda" waves into QRS-ST-T configurations resembling a "tombstone" morphology or "monophasic QRS-ST complex." At the resolution phase of coronary spasm, the QRS-ST-T configurations returned to those without J-waves and were changed by SVE into "lambda" waves. Interestingly, neither ischemia- nor SVE-induced "lambda" waves or SVE-induced "tombstone" morphology or "monophasic QRS-ST complex" were complicated by ventricular tachyarrhythmia.

[Prinzmetal angina. Questions of pathogenesis, clinic, diagnosis and treatment]

Current problems of Prinzmetal angina (vasospastic angina, variant angina) considers in this review. Attention is drawn to early diagnosis, which should be comprehensive, taking into account possible atypical courses and the development of complications. The important role of electrocardiographic monitoring (including using implantable recorders) is highlighted. It is emphasized that patients with cardiac arrhythmias, syncope are at high risk of developing sudden cardiac death. In this category of patients, it is recommended to timely determine the indications for implantation of a cardioverter - defibrillator. Authors consider the prospects of using new methods of treatment of angina pectoris.

Marijuana-induced Coronary Vasospasm with Persistent Inter-coronary Connection: A Case Report and Review of Literature

Coronary vasospasm is a well-known entity causing acute chest syndrome and can lead to myocardial infarction, ventricular arrhythmias, and even sudden cardiac death. While there are extensive case series showing the association of coronary vasospasm with cocaine, studies reporting marijuana-induced coronary vasospasm are limited in number. We herein present a case of coronary vasospasm in a middle-aged African-American male who presented to the emergency department after an episode of syncope. His urine drug screen was positive only for marijuana. He had a transient elevation of ST segments on his EKG with concomitant wall motion abnormalities on echocardiogram and was later found to have vasospasm of coronary arteries on coronary angiogram without any evidence of focal atherosclerotic disease. Another interesting finding was the persistent inter-coronary communication or coronary arcade connecting the left circumflex artery to the right coronary artery. There was bi-directional flow through the inter-coronary communication and hence, we believe this communication prevented our patient from experiencing acute chest symptoms or myocardial infarction. It is important for the clinicians to recognize the association of marijuana with coronary vasospasm. At the same time, these patients should be treated as acute coronary syndromes until proven otherwise by ischemia evaluation.

Acute limb ischemia from gunshot wound secondary to arterial vasospasm

Gunshot wounds are rising in incidence, morbidity, and mortality. It is thought that about half of nonfatal injuries occur in an extremity. Although the incidence is not known, arterial vasospasm can result in acute limb ischemia. We present the case of a 33-year-old man who suffered a gunshot wound to the left lower extremity resulting in arterial vasospasm of the superficial femoral artery. He quickly regained arterial flow, and we were able to manage his acute limb ischemia nonoperatively and to document restoration of flow through serial examinations and Doppler imaging. He was subsequently discharged the next day and is experiencing a full recovery.

Mentha longifolia alleviates experimentally induced angina via decreasing cardiac load

Angina occurs due to imbalance between heart oxygen demand and supply and is associated with serious morbidity and mortality. Here, the possible antianginal effect of Mentha longifolia extract was studied in experimental model of angina. Aerial parts of M. longifolia were extracted, standardized, and given to rats three days before angina. Heart hemodynamics and conductivity were recorded by microtip catheter and surface electrodes. M. longifolia extract significantly alleviated the sustained decline in cardiac contractility after vasopressin exposure. However, M. longifolia did not affect the impaired cardiac dilation after vasopressin. Heart rate was significantly decreased after vasopressin exposure in rats treated with M. longifolia compared with untreated animals. In addition, M. longifolia produced more increase in systolic and diastolic durations after vasopressin exposure compared with untreated animals. Moreover, the plant extract alleviated the ST height changes during vasopressin injection. M. longifolia extract alleviates impaired cardiac function associated with angina through decreasing heart work. PRACTICAL APPLICATIONS: The present study is the first to study the effect of M. longifolia in an experimental model of angina. M. longifolia alleviated the impaired cardiac contractility associated with angina exposure. The antianginal effect of M. longifolia could be through reducing cardiac load. This can be concluded from the decrease in heart rate and the systolic and diastolic cycles elongation after exposure to vasopressin in animals pretreated with M. longifolia. This helps in reducing the associated cardiac ischemia upon exposure to vasopressin as indicated by ST change. This could provide new directions in the management of the serious angina disease.

Vasospastic angina: A literature review of current evidence

Vasospastic angina (VSA) is a variant form of angina pectoris, in which angina occurs at rest, with transient electrocardiogram modifications and preserved exercise capacity. VSA can be involved in many clinical scenarios, such as stable angina, sudden cardiac death, acute coronary syndrome, arrhythmia or syncope. Coronary vasospasm is a heterogeneous phenomenon that can occur in patients with or without coronary atherosclerosis, can be focal or diffuse, and can affect epicardial or microvasculature coronary arteries. This disease remains underdiagnosed, and provocative tests are rarely performed. VSA diagnosis involves three considerations: classical clinical manifestations of VSA; documentation of myocardial ischaemia during spontaneous episodes; and demonstration of coronary artery spasm. The gold standard diagnostic approach uses invasive coronary angiography to directly image coronary spasm using acetylcholine, ergonovine or methylergonovine as the provocative stimulus. Lifestyle changes, avoidance of vasospastic agents and pharmacotherapy, such as calcium channel blockers, nitrates, statins, aspirin, alpha1-adrenergic receptor antagonists, rho-kinase inhibitors or nicorandil, could be proposed to patients with VSA. This review discusses the pathophysiology, clinical spectrum and management of VSA for clinicians, as well as diagnostic criteria and the provocative tests available for use by interventional cardiologists.

2017 ISHNE-HRS expert consensus statement on ambulatory ECG and external cardiac monitoring/telemetry

Ambulatory ECG (AECG) is very commonly employed in a variety of clinical contexts to detect cardiac arrhythmias and/or arrhythmia patterns which are not readily obtained from the standard ECG. Accurate and timely characterization of arrhythmias is crucial to direct therapies that can have an important impact on diagnosis, prognosis or patient symptom status. The rhythm information derived from the large variety of AECG recording systems can often lead to appropriate and patient-specific medical and interventional management. The details in this document provide background and framework from which to apply AECG techniques in clinical practice, as well as clinical research.

Coronary artery vasospasms in a microminipig occurred after placing an ameroid constrictor

A 12-month-old microminipig, weighing 12.6 kg, showed 3 repeated episodes of transient ST-segment elevation in 24 hr Holter electrocardiogram after placing an ameroid constrictor around the left anterior descending coronary artery. Ventricular fibrillation was noticed just after the cessation of the 24 hr Holter-electrocardiogram recording. Direct current defibrillations and cardiopulmonary resuscitation were performed; however, they were unsuccessful, leading to the animal's death. Its heart was excised for macroscopic analysis, which indicated that lumen of the ameroid constrictor was not narrowed and that there was no dissection, embolus or thrombus in the coronary arteries, indirectly suggesting that coronary artery vasospasm may have caused the ischemic attacks. Thus, microminipig may possess some potential to have coronary vasospasm.