ECG phenomenon called the J wave. History, pathophysiology, and clinical significance

An Abnormal ECG Finding in a Patient With COVID-19

This case report presents the electrocardiogram findings of a patient in their 50s with severe COVID-19 pneumonia, hypertension, and diabetes.

Broad Electrocardiogram Syndromes Spectrum: From Common Emergencies to Particular Electrical Heart Disorders

Electrocardiogram (ECG) still remains a very useful diagnostic method in modern cardiology. Its broad availability, noninvasiveness and good sensitivity explain why it plays a capital role in the very beginning of the process of diagnosis for every patient, with or without cardiac-related complaints. For the practitioner, good training in ECG interpretation is mandatory. Sometimes, the ECG trace reveals particular aspects that may cause confusion and complicate decision-making. In this article, we present several less common situations underlying the general context and ECG features. The syndromes studied have a high pathological significance and may range from acute emergencies that call for a rapid therapeutical response to chronic syndromes that require prolonged observation, monitoring and risk stratification.

The Exact Definition of the Boundary between the Rapid and Slow Ejection Phases on ECGs and Accurate Location of the j Point

The aim of the study was to describe the boundary between the phases of rapid and slow ejection in the cardiac cycle and to define the exact location of the j point on ECGs.

Osborn Wave Is Related to Ventricular Fibrillation and Tachycardia in Hypothermic Patients

BACKGROUND

The Osborn wave (OW) is often observed in hypothermic patients; however, whether OW in hypothermic patients is related to the development of fatal ventricular arrhythmia, including ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT), remains undetermined. This study aimed to estimate the association between OW and the incidence of fatal ventricular arrhythmias.Methods and Results: This retrospective study used the Japanese Accidental Hypothermia Network registry database and included 572 hypothermic patients. Patients were divided into the OW group (those with OW) and non-OW group (those without OW). The relationship between the development of fatal arrhythmias and presence of OW was assessed using the chi-squared test. All patients who developed VF/VT (n=10) had OW on electrocardiogram upon hospital arrival. The presence of OW had a sensitivity of 100%, specificity of 47.8%, positive predictive value of 4.0%, and negative predictive value of 100% for VF/VT development. The in-hospital mortality rate was 22.3% in the OW group and 21.2% in the non-OW group (P=0.781).

CONCLUSIONS

OW was observed in all hypothermic patients with VF/VT. The occurrence of ventricular arrhythmias is highly unlikely in the absence of OW on the electrocardiogram. Although the presence of OW might be used to predict these fatal arrhythmias in hypothermic patients, there was no association between the presence of OW and in-hospital mortality.

When the factory shuts down

CLINICAL INTRODUCTION

A 56-year-old man without known medical history was brought to our ED after he was found next to his bed, agitated and with waxing and waning consciousness. He has been bedbound for 5 days after a long-standing period of malnutrition. Physical examination reveals Kussmaul breathing, heart rate of 62/min and blood pressure of 135/100 mm Hg, normal cardiac, abdominal and a non-focal neurological examination other than confusion and altered level of consciousness. An EKG was performed (figure 1).emermed;36/1/51/F1F1F1Figure 1EKG at presentation in our ED.

QUESTION

What abnormalities are the clues to the severity of his condition? How would you confirm your suspicion?The minimally prolonged QTc time.The subtle horizontal ST segment elevation in V2 and V3.The subtle positive deflection at the J point.Nothing, this EKG is not interpretable because of the movement of baseline.

Osborn wave in hypothermia and relation to mortality

BACKGROUND & AIM

The aim of this study was to compare hypothermia patients with and without an Osborn wave (OW) in terms of physical examination findings, laboratory results, and clinical survival.

METHODS

The study was carried out retrospectively on hypothermic patients. The hypothermic patients were divided into two groups. Group 1 comprised patients with OW on electrocardiogram (ECG), and Group 2 comprised patients without OW on ECG. The Mann-Whitney U test was used to compare the two groups, and the relationships between the variables and the presence of OW and mortality were analyzed with ANOVA. A value of p < 0.05 was considered statistically significant.

RESULTS

OW was detected on ECG of 41.9% of the patients (Group 1). The mean body temperature was 30.8 ± 4.1 °C in Group 1 and 33.3 ± 1.6 °C in Group 2 (p = 0.106). The mean creatinine level was 1.01 ± 0.6 mg/dl in Group 1 and 0.73 ± 0.5 mg/dl in Group 2 (p = 0.046). The mean bicarbonate level was 15.9 ± 3.8 mmol/l in Group 1 and 18.6 ± 3.5 mmol/l in Group 2 (p = 0.038). A relationship was determined between the presence of OW and pH, bicarbonate, and creatinine levels (p = 0.026; 0.013; 0.042, respectively). The mortality rate was 69.2% in Group 1 and 77.8% in Group 2 (p = 0.689).

CONCLUSION

Although there is a relationship between the decrease in bicarbonate levels, changes in kidney functions that cause acidosis, and the presence of OW, it has no effect on mortality. The presence of OW in hypothermic patients is insufficient to make a decision regarding mortality.

Induction of hibernation-like hypothermia by central activation of the A1 adenosine receptor in a non-hibernator, the rat

Central adenosine A1-receptor (A1AR)-mediated signals play a role in the induction of hibernation. We determined whether activation of the central A1AR enables rats to maintain normal sinus rhythm even after their body temperature has decreased to less than 20 °C. Intracerebroventricular injection of an adenosine A1 agonist, N6-cyclohexyladenosine (CHA), followed by cooling decreased the body temperature of rats to less than 20 °C. Normal sinus rhythm was fundamentally maintained during the extreme hypothermia. In contrast, forced induction of hypothermia by cooling anesthetized rats caused cardiac arrest. Additional administration of pentobarbital to rats in which hypothermia was induced by CHA also caused cardiac arrest, suggesting that the operation of some beneficial mechanisms that are not activated under anesthesia may be essential to keep heart beat under the hypothermia. These results suggest that central A1AR-mediated signals in the absence of anesthetics would provide an appropriate condition for maintaining normal sinus rhythm during extreme hypothermia.

The Mechanism Enabling Hibernation in Mammals

Some rodents including squirrels and hamsters undergo hibernation. During hibernation, body temperature drops to only a few degrees above ambient temperature. The suppression of whole-body energy expenditure is associated with regulated, but not passive, reduction of cellular metabolism. The heart retains the ability to beat constantly, although body temperature drops to less than 10 °C during hibernation. Cardiac myocytes of hibernating mammals are characterized by reduced Ca²⁺ entry into the cell membrane and a concomitant enhancement of Ca²⁺ release from and reuptake by the sarcoplasmic reticulum. These adaptive changes would help in preventing excessive Ca²⁺ entry and its overload and in maintaining the resting levels of intracellular Ca²⁺. Adaptive changes in gene expression in the heart prior to hibernation may be indispensable for acquiring cold resistance. In addition, protective effects of cold-shock proteins are thought to have an important role. We recently reported the unique expression pattern of cold-inducible RNA-binding protein (CIRP) in the hearts of hibernating hamsters. The CIRP mRNA is constitutively expressed in the heart of a nonhibernating euthermic hamster with several different forms probably due to alternative splicing. The short product contained the complete open reading frame for full-length CIRP, while the long product had inserted sequences containing a stop codon, suggesting production of a C-terminal deletion isoform of CIRP. In contrast to nonhibernating hamsters, only the short product was found in hibernating animals. Thus, these results indicate that CIRP expression in the hamster heart is regulated at the level of alternative splicing, which would permit a rapid increment of functional CIRP when entering hibernation. We will summarize the current understanding of the cold-resistant property of the heart in hibernating animals.

The relationship between J waves and contact of lung cancer with the heart

BACKGROUND

J waves result mainly from an increased density of transient outward current (Ito ). Mechanical stretch to the heart activates multiple signal transduction pathways, in which Ito may be involved. The purpose of this study was to test the hypothesis that mechanical contact of lung cancer with the heart may manifest J waves.

METHODS

We reviewed 12-lead electrocardiograms to examine whether J waves were associated with contact of lung cancer with the heart. J waves were defied as an elevation of ≥0.1 mV at the junction between QRS complex and ST segment with either notching or slurring morphology. The locational interaction between lung cancer and the heart was determined by computed tomography image.

RESULTS

A total of 264 patients (176 men; mean 68.5 ± 10.7 years) with lung cancer were evaluated. The prevalence of J waves was 25.4% in the total population. J waves were present in 40 of 44 (90.9%) patients with the contact. In contrast, J waves were present in 25 of 220 (11.4%) patients without the contact. The sensitivity and specificity of the contact for J waves were 90.9% and 88.6%, respectively. The odds ratio of the contact with the heart to the presence of J waves was 78 (95% confidence interval 25.7-236.4). The appearance of J waves that coincided with the development of lung cancer was observed in 12 patients.

CONCLUSION

The presence of J waves was associated with the contact of lung cancer with the heart.

A female patient with hypokalaemia-induced J wave syndrome: An unusual case report

RATIONALE

Prominent J waves can be seen in life-threatening cardiac arrhythmias such as Brugada syndrome, early repolarization syndrome, and ventricular fibrillation. We herein present an unusual case report of hypokalemia-induced J wave syndrome and ST (a part of ECG) segment elevation.

PATIENTS CONCERNS

A 52-year-old woman with chief complaints of chest pain for 2 hours and diarrhea showed a marked hypokalemia (2.8 mmol/L) and slightly elevated creatine kinase-MB (CK-MB) (57.5 U/L). The electrocardiographic (ECG) recording was normal upon admission and computed tomography (CT) aorta angiography excluded an aorta dissection. ECG done 17 hours after admission showed ST segment elevation and elevated J wave in leads II, III and aVF, and fusion of T and U wave in all leads.

DIAGNOSIS

We first thought that the diagnosis of this patient was acute myocardial syndrome.

INTERVENTION

Potassium chloride and oflocaxin treatment was given to the patient.

OUTCOMES

Laboratory test showed the level of serum potassium ion increased to 3.4 mmol/L and CK-MB did not have any significant change. The infusion of potassium chloride-induced disappearance of the elevated J wave, although QT (a part of ECG) intervals were still longer than that upon admission.

LESSONS

This case tells us that hypokalaemia might induce J wave and elevated ST segments which should be distinguished from acute myocardial syndrome.

J Wave Syndromes: History and Current Controversies

The concept of J wave syndromes was first proposed in 2004 by Yan et al for a spectrum of electrocardiographic (ECG) manifestations of prominent J waves that are associated with a potential to predispose affected individuals to ventricular fibrillation (VF). Although the concept of J wave syndromes is widely used and accepted, there has been tremendous debate over the definition of J wave, its ionic and cellular basis and arrhythmogenic mechanism. In this review article, we attempted to discuss the history from which the concept of J wave syndromes (JWS) is evolved and current controversies in JWS.

Role of Early Repolarization Pattern in Increasing Risk of Death

Background

An early repolarization pattern (ERP) has been hypothesized to be arrhythmogenic in experimental studies, but the prognostic significance of the ERP in the general population is controversial. We performed a meta‐analysis to examine the link between ERP and the risk of sudden cardiac arrest (SCA), cardiac death, and death from any cause.

Methods and Results

We performed a literature search using MEDLINE (January 1, 1966 to July 31, 2015) and EMBASE (January 1, 1980 to July 31, 2015) with no restrictions. Studies that reported relative risk (RR) estimates with 95% confidence intervals (CIs) for the associations of interest were included. Sixteen studies involving 334 524 subjects were identified. Compared with those without ERP, subjects with ERP experienced significantly increased risk for developing SCA (RR 2.18; 95% CI 1.29–3.68), cardiac death (RR 1.48; 95% CI 1.06–2.07), and death from any cause (RR 1.21; 95% CI 1.02–1.42), respectively. The increased risk was present predominantly in Asians and whites but not in African Americans. ERP with J‐point elevation in inferior leads, notching configuration, and horizontal or descending ST segment connote higher risk. ERP was associated with an absolute risk increase of 139.6 (95% CI 130.3–149.3) additional SCAs per 100 000 person‐years and responsible for 7.3% (95% CI 1.9–15.2) of SCA in the general population.

Conclusions

ERP is associated with significant increased risk for SCA, cardiac death, and death from any cause. Future studies should focus on understanding the exact mechanisms for the arrhythmia risk and developing reliable tools for risk stratification.

Electrocardiographic Manifestations in three Psychiatric patients with Hypothermia - Case Report

Hypothermia occurs when the core body temperature falls below 35°C, which, in severe cases, can lead to electrocardiographic changes. Several conditions that occur in the psychiatric population increase the risk of hypothermia. This risk can be further increased by the use of several classes of medications such as antipsychotics, beta-adrenergic antagonists and benzodiazepines. We report on three psychiatric patients who were admitted for hypothermia and developed electrocardiographic manifestations (sinus bradycardia, QT prolongation and Osborn waves), which completely resolved after treatment.

The prevalence of the electrocardiographic J wave in the Petit Basset Griffon Vendéen compared to 10 different dog breeds

INTRODUCTION

To investigate the prevalence and amplitudes of the electrocardiographic J wave in the Petit Basset Griffon Vendéen compared to 10 other dog breeds.

ANIMALS

Electrocardiograms from 206 healthy dogs representing 11 dog breeds were included in the study. Besides Petit Basset Griffon Vendéen (PBGV; n = 23) 10 other dog breeds were included.

MATERIALS AND METHODS

An electrocardiogram ruler was used for measuring the amplitudes of the J waves. The definition of a J wave was a positive deflection at the J point of ≥0.1 mV in more than 1 lead of the bipolar standard limb leads (I, II, III) or the unipolar standard limb leads (aVL and aVF).

RESULTS

The prevalence of J waves in the PBGV (n = 23) was 91% (n = 21, standard error (SE) = 5.9%), which was significantly higher compared to seven other dog breeds (p < 0.05). The overall prevalence of J waves in all 11 dog breeds (n = 206) was 43% (n = 89, robust SE = 7.8%). There was no significant difference in the prevalence between male and female dogs (p = 0.79). Neither did age (p = 0.22) nor heart rate (p = 0.25) significantly affect the prevalence of J wave.

CONCLUSIONS

The PBGV had the highest prevalence of J waves and the highest amplitudes compared to 10 other dog breeds. However J waves were also seen in other breeds. Therefore, J waves may be considered a normal variant on the canine electrocardiogram and should not be interpreted as cardiac disease.

A comprehensive literature review on hypothermia and early extubation following coronary artery bypass surgery

PURPOSE

The purpose of this study was to comprehensively review the literature addressing the physiological effects of hypothermia and its association with the appropriate core body temperature for extubation following coronary artery bypass surgery.

METHODS

The electronic databases MEDLINE, CINAHL and Web of Science via OVID were used to identify studies for the literature review. Search words used included 'core temperature', 'arrhythmia', 'cardiac', 'cardiac surgery', 'hypothermia', 'extubation', 'temperature', 'rewarming', and 'shivering'.

RESULTS

The literature search yielded 55 articles that met our inclusion criteria. No studies specifically identified the benefit of extubation at 36.5 ° C. Although temperatures varied, arrhythmias resulting from hypothermia were not reported until core body temperature dropped below 33 ° C.

CONCLUSION

This comprehensive literature review suggests extubation at lower temperatures (between 34 ° C and 36 ° C) may be viable if shivering and other factors known to contribute to myocardial stress can be controlled. These findings offer the possibility of earlier extubation which may promote beneficial health outcomes.

Out in the cold: the hypothermic heart response

We present an interesting case of a 49-year-old woman with hypothermia and associated Osborn waves (also called J waves) on ECG. She was found on the floor of her home and difficult to arouse. On arrival to the emergency department (ED), her rectal temperature was 87.5°F. ECG showed Osborn waves in diffuse leads. She was intubated in the ED and was started on vasopressor support for hypotension refractory to intravenous fluid boluses. She was transferred to the critical care unit for continued respiratory and cardiovascular support. With active external rewarming her core body temperature continued to improve. Blood pressure also improved and vasopressor was tapered off. She was extubated and was transferred to the medical floor for continued supportive care. Osborn waves on ECG resolved within 12 h of achieving normal range body temperature. The patient was eventually discharged home with medical follow-up.

SIRT2 induces the checkpoint kinase BubR1 to increase lifespan

Mice overexpressing the mitotic checkpoint kinase gene BubR1 live longer, whereas mice hypomorphic for BubR1 (BubR1(H/H)) live shorter and show signs of accelerated aging. As wild-type mice age, BubR1 levels decline in many tissues, a process that is proposed to underlie normal aging and age-related diseases. Understanding why BubR1 declines with age and how to slow this process is therefore of considerable interest. The sirtuins (SIRT1-7) are a family of NAD(+)-dependent deacetylases that can delay age-related diseases. Here, we show that the loss of BubR1 levels with age is due to a decline in NAD(+) and the ability of SIRT2 to maintain lysine-668 of BubR1 in a deacetylated state, which is counteracted by the acetyltransferase CBP. Overexpression of SIRT2 or treatment of mice with the NAD(+) precursor nicotinamide mononucleotide (NMN) increases BubR1 abundance in vivo. Overexpression of SIRT2 in BubR1(H/H) animals increases median lifespan, with a greater effect in male mice. Together, these data indicate that further exploration of the potential of SIRT2 and NAD(+) to delay diseases of aging in mammals is warranted.

Electrocardiographic changes in hypothermia: a review

Hypothermia is a common environmental emergency encountered by physicians and is associated with a variety of electrocardiographic (ECG) abnormalities. The classic and well-known ECG manifestations of hypothermia include the presence of J (Osborn) waves, interval (PR, QRS, QT) prolongation, and atrial and ventricular arrhythmias. There are less well defined and known ECG signs of hypothermia, which in fact may simulate findings of acute coronary ischemia, Brugada syndrome, or even pericarditis. Although classical ECG changes seen in hypothermia certainly serve as an important clinical clue for prompt identification and management of this easily curable life-threatening entity, physicians should, however, be able to maintain a high suspicion for recognition and differentiation of less common ECG abnormalities encountered in hypothermia. This article aims to provide a detailed review of all the potential ECG abnormalities that may be encountered in accidental and iatrogenic hypothermia.

ECG Changes Due to Hypothermia Developed After Drowning: Case Report

Drowning is one of the fatal accidents frequently encountered during the summer and is the most common cause of accidental death in the world. Anoxia, hypothermia, and metabolic acidosis are mainly responsible for morbidty. Cardiovascular effects may occur secondary to hypoxia and hypothermia. Atrial fibrillation, sinus dysrhythmias (rarely requiring treatment), and, in serious cases, ventricular fibrillation or asystole may develop, showing as rhythm problems on electrocardiogram and Osborn wave can be seen, especially during hypothermia. A 16-year-old male patient who was admitted to our hospital's emergency service with drowning is presented in this article. In our case, ventricular fibrillation and giant J wave (Osborn wave) associated with hypothermia developed after drowning was seen. We present this case as a reminder of ECG changes due to hypothermia that develop after drowning. Response to cardiopulmonary resuscitation after drowning and hypothermia is not very good. Mortality is very high, so early resuscitation and aggressive treatment of cardiovascular and respiratory problems are important for life.

Dynamic J-Point Elevation Associated with Epileptic Hemiplegia: The Osborn Wave of Todd's Paralysis

THIS CASE REPORT EXPOSES A PHENOMENON WHICH, ALTHOUGH PROPOSED, HAS NOT BEEN DESCRIBED IN CLINICAL LITERATURE: transient postictal hemiplegia (Todd's paralysis) with concomitant electrocardiographic J-point deflection (Osborn waves). Although typically associated with hypothermia, a prominent J-wave on the electrocardiogram (ECG) results from a transmyocardial voltage gradient during ventricular repolarization. Rarely, the Osborn wave may be observed in a non-hypothermic setting such as hypercalcemia or cerebral hemorrhage. Transient postictal hemiplegia has been attributed to localized cerebral hypoperfusion resulting from motor cortex exhaustion following an epileptic seizure. The same central nervous system autonomic dysfunction has been theorized to produce subendocardial hypoperfusion with electrocardiographic change and cardiac troponin T elevation. This is the first described ECG evidence of a dynamically displaced J-point in the setting of postictal hemiplegia.

Early repolarization and its modification by preexcitation in two patients with intermittent Wolff-Parkinson-White syndrome

We report two cases of intermittent Wolff-Parkinson-White (WPW) syndrome. In one patient, early repolarization (ER) was masked during preexcitation whereas in the other, J wave-like notches were observed in the right precordial leads only during preexcitation. The clinical significance of ER is not apparent in WPW syndrome but some possible mechanisms are discussed.

Giant osborn waves seen in a patient with hypothermia associated with status epilepticus-induced diffuse cerebral injury

This is a case of a patient with hypothermia associated with status epilepticus-induced diffuse cerebral injury, with electrocardiogram showing Osborn waves. The electrocardiogram changes resolved as the patient became normothermic.

Evolving J waves prior to ventricular fibrillation postoperative coronary bypass

A 74-year-old man without history of ventricular arrhythmias underwent coronary bypass surgery for 3-vessel disease. On the 4th postoperative day, he developed ventricular fibrillation (VF). His monitored ECG showed no elevation of the ST-segment and no prolongation of QT interval, but evolving J waves prior to VF were shown. These J waves gradually decreased after defibrillation. The subsequent angiography revealed patent grafts and normal left ventricular function. J waves reappeared in inferior leads when contrast medium was injected into the coronary artery. Therefore, evolving J wave can be a marker of latent ischemia and a predictor of VF.

Severe bradycardia with a prominent J wave refractory to atropine: was it a cause or a result of a fall? A case report and a brief review on the treatment of hypothermia

We report on an eighty five year old male who had presented with bradycardia and a prominent J wave on EKG. Initial attemps to treat bradycardia with atropine were unsuccessful and on further evaluation the patient was found to have hypothermia.

Recommendations for interpretation of 12-lead electrocardiogram in the athlete

Cardiovascular remodelling in the conditioned athlete is frequently associated with physiological ECG changes. Abnormalities, however, may be detected which represent expression of an underlying heart disease that puts the athlete at risk of arrhythmic cardiac arrest during sports. It is mandatory that ECG changes resulting from intensive physical training are distinguished from abnormalities which reflect a potential cardiac pathology. The present article represents the consensus statement of an international panel of cardiologists and sports medical physicians with expertise in the fields of electrocardiography, imaging, inherited cardiovascular disease, cardiovascular pathology, and management of young competitive athletes. The document provides cardiologists and sports medical physicians with a modern approach to correct interpretation of 12-lead ECG in the athlete and emerging understanding of incomplete penetrance of inherited cardiovascular disease. When the ECG of an athlete is examined, the main objective is to distinguish between physiological patterns that should cause no alarm and those that require action and/or additional testing to exclude (or confirm) the suspicion of an underlying cardiovascular condition carrying the risk of sudden death during sports. The aim of the present position paper is to provide a framework for this distinction. For every ECG abnormality, the document focuses on the ensuing clinical work-up required for differential diagnosis and clinical assessment. When appropriate the referral options for risk stratification and cardiovascular management of the athlete are briefly addressed.

Hypothermia with Osborn waves in Parkinson's disease

Autonomic dysfunction in patients with Parkinson's disease has been recognized since the original description by James Parkinson in 1817. In the present case, an 80-year-old woman who had been diagnosed with Parkinson's disease 3 years earlier (Hoehn and Yahr stage III) was admitted with a few days history of lethargy and bradykinesia. She lived in a heated house and used an electric blanket at night. On examination, her core temperature was 29.7 degrees C. Her initial ECG showed sinus bradycardia, QT prolongation, and Osborn waves, which disappeared after rewarming. Successful rewarming was achieved with an external rewarming blanket over 12 hours. Follow-up ECG showed resolution of the Osborn waves. In Parkinson's disease, rapidly progressive hypothermia can occur in a well-heated house. Determining a rewarming strategy is a complex but not insurmountable task. In the elderly, the use of careful active external rewarming and a low stress strategy may be recommended.