Incidence, Pathophysiology, and Treatment of Complications During Dobutamine-Atropine Stress Echocardiography

Practice guidance for stress echocardiography

Stress echocardiography has been one of the most promising methods for the diagnosis of ischemic heart disease, hypertrophic cardiomyopathy, and pulmonary hypertension. The Japanese Society of Echocardiography produced practical guidance for the implementation of stress echocardiography in 2018. At that time, stress echocardiography was not yet widely disseminated in Japan; therefore, the 2018 practical guidance for the implementation of stress echocardiography included a report on stress echocardiography and a specific protocol to promote its use at many institutions in Japan in the future. And now, an era of renewed interest and enthusiasm surrounding the diagnosis and treatment of valvular heart disease and heart failure with preserved ejection fraction (HFpEF) has come, which are driven by emerging trans-catheter procedures and new recommended guideline-directed medical therapy. Based on the continued evidence of stress echocardiography, the new practical guideline that describes the safe and effective methodology of stress echocardiography is now created by the Guideline Development Committee of the Japanese Society of Echocardiography and is designed to expand the use of stress echocardiography for valvular heart disease and HFpEF, as well as ischemic heart disease, hypertrophic cardiomyopathy, and pulmonary hypertension. The readers are encouraged to perform stress echocardiography which will enhance the diagnosis and management of these patients.

Safety of dobutamine or adenosine stress cardiac magnetic resonance imaging in patients with left ventricular thrombus

BACKGROUND

Left ventricular (LV) thrombus formation is a common but potentially serious complication, typically occurring after myocardial infarction. Due to perceived high thromboembolic risk and lack of safety data, stress cardiac magnetic resonance (CMR) imaging especially with dobutamine is usually avoided despite its high diagnostic yield. This study aimed to investigate the characteristics, safety and outcome of patients with LV thrombus undergoing dobutamine or vasodilator stress CMR.

METHODS

Patients undergoing stress CMR with concomitant LV thrombus were retrospectively included. Risk factors, comorbidities, and previous embolic events were recorded. Periprocedural safety was assessed for up to 48 h following the examination. Major adverse cardiac events (MACE) 12 months before the diagnosis were compared to 12 months after the exam and between patients and a matched control group. Additionally, patients were followed up for all-cause mortality.

RESULTS

95 patients (78 male, 65 ± 10.7 years) were included. Among them, 43 patients underwent dobutamine (36 high-dose, 7 low-dose) and 52 vasodilator stress CMR. Periprocedural safety was excellent with no adverse events. During a period of 24 months, 27 MACE (14.7%) occurred in patients and controls with no statistical difference between groups. During a median follow-up of 33.7 months (IQR 37.6 months), 6 deaths (6.3%) occurred. Type of stress agent, thrombus mobility, or protrusion were not correlated to embolic events or death.

CONCLUSION

The addition of a stress test to a CMR exam is safe and does increase the generally high cardioembolic event rate in LV thrombus patients. Therefore, it is useful to support reperfusion decision-making.

Myocardial Injury after Non-Cardiac Surgery in Patients Who Underwent Open Repair for Abdominal Aortic Aneurysm: A Retrospective Study

BACKGROUND

Myocardial injury after non-cardiac surgery (MINS) has been known to be associated with mortality in various surgical patients; however, its prognostic role in abdominal aortic aneurysm (AAA) open repair remains underexplored. This study aimed to investigate the role of MINS as a predictor of mortality in patients who underwent AAA open repair.

METHODS

This retrospective study investigated 352 patients who underwent open repair for non-ruptured AAA. The predictors of 30-day and 1-year mortalities were investigated using logistic regression analysis.

RESULTS

MINS was diagnosed in 41% of the patients after AAA open repair in this study. MINS was an independent risk factor of 30-day mortality (odds ratio [OR]: 10.440, 95% confidence interval [CI]: 1.278-85.274, p = 0.029) and 1-year mortality (OR: 5.189, 95% CI: 1.357-19.844, p = 0.016). Kaplan-Meier survival curves demonstrated significantly lower overall survival rates in patients with MINS compared to those without MINS (p = 0.003).

CONCLUSION

This study revealed that MINS is a common complication after AAA open repair and is an independent risk factor of 30-day and 1-year mortalities. Patients with MINS have lower overall survival rates than those without MINS.

Combined low-dose dobutamine and exercise stress echocardiography: a new hybrid protocol to detect inducible ischaemia

Aims

Myocardial response to stress echocardiography may be elicited physiologically, through exercise, or pharmacologically, often with dobutamine. Both have advantages but also limitations due to reduced exercise capacity or side-effects to stressor agent/lack of closeness to true pathophysiology of ischaemic cascade. We have combined low-dose dobutamine and exercise, creating a 'hybrid' protocol to utilize the advantages of both techniques and limit the drawbacks. The aim of the study was to evaluate its safety and feasibility.

Methods and results

In the hybrid protocol, low-dose dobutamine infusion (up to 10 µg/kg/min) is enhanced by supine bicycle exercise at 3-min increments of workload of 25 W to achieve target heart rate (THR). We analysed safety and outcome data for all the patients who underwent this protocol from 2017 to 2022. Out of 835, 727 (87.1%) patients referred for evaluation of ischaemia underwent the hybrid protocol. The median age was 61 years old and 61% (442/727) were men. The median exercise time was 11 (9-13.5) min with a median maximum workload of 100 W (75-125). Out of 727, 670 (92.2%) achieved THR. Atropine was not used. Out of 727, 192 (26.4%) of studies were positive for ischaemia. Out of 122, 102 (83.6%) with positive stress who underwent invasive angiography had significant coronary disease. The incidence of complications was low: 1/727-severe arrhythmia, 5/727 (0.7%) developed a vasovagal episode, and 14/727 (1.9%) had a hypertensive response to exercise.

Conclusion

Our findings suggest that this protocol is safe, feasible, and has a high success rate in achieving THR.

Exaggerated Systolic Blood Pressure Increase with Exercise and Myocardial Ischemia on Exercise Stress Echocardiography

BACKGROUND

Central Illustration : Exaggerated Systolic Blood Pressure Increase with Exercise and Myocardial Ischemia on Exercise Stress Echocardiography ESBPRE: exaggerated systolic blood pressure response to exercise; HR: heart rate; SBP: systolic blood pressure.

BACKGROUND

The association between exaggerated systolic blood pressure response to exercise (ESBPRE) and myocardial ischemia is controversial and little studied in patients with established or suspected chronic coronary syndrome.

OBJECTIVE

To verify the relationship between myocardial ischemia and ESBPRE in patients undergoing exercise stress echocardiography (ESE).

METHODS

This is a cross-sectional study with 14,367 patients undergoing ESE, from January 2000 to January 2022, divided into the following 2 groups: G1, composed of patients whose peak systolic pressure increased ≥ 90 mmHg (value corresponding to the 95th percentile of the study population), and G2, patients who did not demonstrate an exaggerated hypertensive response. The groups were compared using Student's t and chi-square tests. P values < 0.05 were considered significant. Logistic regression was also performed to identify independent risk factors for myocardial ischemia, ESBPRE, complaints of typical chest pain prior to the exam, and angina during the test.

RESULTS

Of the 14,367 patients, 1,500 (10.4%) developed ESBPRE, and 7,471 (52.0%) were female. The percentages of previous complaints of typical chest pain, angina during the test, and myocardial ischemia in patients with ESBPRE were 5.8%, 2.4% and 18.1%, compared to 7.4%, 3.9%, and 24.2%, in patients without ESBPRE, respectively (p = 0.021,p = 0.004, p < 0.001). In multivariate analysis, ESBPRE was independently associated with a lower probability of myocardial ischemia (odds ratio: 0.73; 95% confidence interval: 0.58 to 0.93; p = 0.009).

CONCLUSION

Exaggerated increase in systolic blood pressure during ESE may be a marker for excluding myocardial ischemia.

The Utility of Low-Dose-Dobutamine Stress Echocardiography in Patients with Heart Failure with Reduced Ejection Fraction: An Update

Despite significant advancements in medical therapy, heart failure with reduced ejection fraction (HFrEF) continues to be a significant cause of death and disability. Reversible ischaemic left ventricular dysfunction due to viable myocardium is one such contributing factor. In these cases, coronary revascularization has shown promise in improving left ventricular function and prognosis. For patients with HFrEF and wide QRS, cardiac resynchronization therapy (CRT) is an effective option to address electromechanical dyssynchrony. However, approximately 30% of patients do not respond positively to CRT, highlighting the need to refine candidate selection for this treatment. In some patients with reduced HFrEF, there is a condition known as classical low-flow, low-gradient aortic stenosis (AS) that may be observed. This condition is characterized by a low transaortic flow, which leads to reductions in both the transaortic mean gradient and aortic valve area. Decision-making regarding revascularization, CRT, and pharmacological treatment play a crucial role in managing HFrEF. Cardiac imaging can be valuable in guiding decision-making processes and assessing the prognosis of patients with HFrEF. Among the imaging modalities, dobutamine stress echocardiography has come a long way in establishing itself as a feasible, safe, effective, relatively cheap non-invasive technique. The aim of this review is to explore the current literature on the utility of low-dose stress echocardiography in diagnosing and prognosticating patients with HFrEF.

Complications of exercise and pharmacologic stress echocardiography

Stress echocardiography is a diagnostic cardiovascular exam that is commonly utilized for multiple indications, including but not limited to the assessment of obstructive coronary artery disease, valvular disease, obstructive hypertrophic cardiomyopathy, and diastolic function. Stress echocardiography can be performed via both exercise and pharmacologic modalities. Exercise stress is performed with either treadmill or bicycle-based exercise. Pharmacologic stress is performed via either dobutamine or vasodilator-mediated (i.e., dipyridamole, adenosine) stress testing. Each of these modalities is associated with a low overall prevalence of major, life-threatening adverse outcomes, though adverse events are most common with dobutamine stress echocardiography. In light of the recent COVID-19 pandemic, the risk of infectious complications to both the patient and stress personnel cannot be negated; however, when certain precautions are taken, the risk of infectious complications appears minimal. In this article, we review each of the stress echocardiographic modalities, examine major potential adverse outcomes and contraindications, assess the risks of stress testing in the setting of a global pandemic, and examine the utilization and safety of stress testing in special patient populations (i.e., language barriers, pediatric patients, pregnancy).

Myocardial injury in stress echocardiography: Comparison of dobutamine, dipyridamole and dynamic stressors-single center study

OBJECTIVES

In stress echocardiography (SE), dipyridamole (DIP) and dynamic stress (ExSE) are reported as being safer than dobutamine stress echocardiography (DSE). We investigated whether these commonly used stressors cause myocardial injury, measured by high sensitivity troponin T (hsTnT).

METHODS

One hundred and thirty five patients (DSE n = 46, ExsE n = 46, DIP n = 43) with negative result of SE were studied. The exclusion criteria were known ischaemic heart disease (IHD), baseline wall motion abnormalities, left ventricle systolic dysfunction/regional wall motion abnormalities, septum/posterior wall ≥13 mm, diabetes/pre-diabetes, baseline hsTnT level ≥14 ng/L, baseline blood pressure ≥160/100 mmHg, peak pulmonary pressure ≥45mmHg, eGFR <1ml/s/1.73m² , more than mild to moderate valvular disease and dobutamine side effects. HsTnT was measured before and 180 minutes after the test.

RESULTS

All patients had low pre-test probabilities of having obstructive IHD. HsTnT increased in DSE, less so in ExSE, and was unchanged in the DIP group (∆hsTnT 9.4 [1.5-58.6], 1.1 [-0.9-15.7], -0.1 [-1.4-2.1] ng/L, respectively, p<0.001). In DSE, the ∆hsTnT was associated with peak dobutamine dose (r = 0.30, p = 0.045), test length (r = 0.43, p = 0.003) and atropine use (p<0.001). In ExSE, the hsTnT increase was more likely in females (p = 0.012) and the elderly (>65 years) (r = 0.32, p = 0.03); no association was found between atropine use (p = 0.786) or test length and ∆hsTnT (r = 0.10, p = 0.530).

CONCLUSIONS

DSE is associated with myocardial injury in patients with negative SE, no injury was observed in DIP and only mild case in ExSE. Whether myocardial injury is causative of the higher reported adverse event rates in DSE remains to be determined.

Non-invasive Ischaemia Testing in Patients With Prior Coronary Artery Bypass Graft Surgery: Technical Challenges, Limitations, and Future Directions

Coronary artery bypass graft (CABG) surgery effectively relieves symptoms and improves outcomes. However, patients undergoing CABG surgery typically have advanced coronary atherosclerotic disease and remain at high risk for symptom recurrence and adverse events. Functional non-invasive testing for ischaemia is commonly used as a gatekeeper for invasive coronary and graft angiography, and for guiding subsequent revascularisation decisions. However, performing and interpreting non-invasive ischaemia testing in patients post CABG is challenging, irrespective of the imaging modality used. Multiple factors including advanced multi-vessel native vessel disease, variability in coronary hemodynamics post-surgery, differences in graft lengths and vasomotor properties, and complex myocardial scar morphology are only some of the pathophysiological mechanisms that complicate ischaemia evaluation in this patient population. Systematic assessment of the impact of these challenges in relation to each imaging modality may help optimize diagnostic test selection by incorporating clinical information and individual patient characteristics. At the same time, recent technological advances in cardiac imaging including improvements in image quality, wider availability of quantitative techniques for measuring myocardial blood flow and the introduction of artificial intelligence-based approaches for image analysis offer the opportunity to re-evaluate the value of ischaemia testing, providing new insights into the pathophysiological processes that determine outcomes in this patient population.

Safety of SF6(SonoVue®) Contrast Agent on Pharmacological Stress Echocardiogram

Fundamento

Em 2007, a Food and Drug Administration (FDA) determinou revisões sobre segurança dos agentes de contraste ecocardiográfico (ACE) disponíveis no mercado após relatos de mortes. Ao longo desses anos, diversos estudos comprovaram a segurança dos ACE, porém com poucos estudos relacionados ao SonoVue^®.

Objetivos

Avaliar a segurança do SonoVue^® durante o ecocardiograma sob estresse farmacológico (EEF) por meio da análise da incidência de reações alérgicas e da comparação entre os grupos quanto ao surgimento de arritmia, efeitos colaterais menores e eventos adversos.

Métodos

Estudo observacional, prospectivo, no qual 2.346 pacientes foram submetidos ao EEF e divididos em dois grupos: grupo 1 com ACE (n=1.099) e grupo 2 sem ACE (n=1.247). Os pacientes foram avaliados durante o EEF – 24 horas e 30 dias. Foi definido p significativo quando <0,05.

Resultados

O grupo 1 apresentou efeitos colaterais mais leves, como cefaleia (5/0,5% vs. 19/1,5%, p=0,012) e hipertensão reativa (3/0,3% vs . 19/1,5%, p=0,002), menos arritmias como extrassístoles ventriculares (180/16,4% vs . 247/19,8%, p=0,032) e taquicardia paroxística supraventricular (2/0,2% vs . 15/1,2%, p=0,003), assim como nenhum evento adverso como infarto agudo do miocárdio (IAM) e óbito. No grupo 2, um paciente apresentou IAM <24h (1/01%) e dois óbitos <30 dias (2/0,1%). Urticária relacionada ao SonoVue^® foi observada em 3 (0,3%) pacientes sem reação anafilática.

Conclusão

SonoVue^® demonstrou segurança durante o EEF, não sendo observados morte, IAM ou reação anafilática. Observou-se menor incidência de efeitos colaterais mais leves e arritmias no grupo que utilizou o ACE, assim como baixa incidência de reações alérgicas leves.

Effects of Copaiba Oil in Peripheral Markers of Oxidative Stress in a Model of Cor Pulmonale in Rats

Fundamento

Até o presente momento, os efeitos sistêmicos do óleo de copaíba jamais foram documentados no Cor pulmonale induzido por monocrotalina.

Objetivos

Investigar os efeitos do óleo de copaíba nos marcadores periféricos de stress oxidativo em ratos com Cor pulmonale.

Métodos

Ratos Wistar machos (170±20g, n=7/grupo) foram divididos em quatro grupos: controle (CO), monocrotalina (MCT), óleo de copaíba (O), e monocrotalina + óleo de copaíba (MCT-O). Foi administrada a MCT (60 mg/kg i.p.) e, depois de uma semana, foi iniciado o tratamento com óleo de copaíba (400 mg/kg/day-gavagem-14 dias). Foi realizado o ecocardiograma e, depois disso, foi coletado sangue do tronco para a realização de avaliações de stress oxidativo. Análise estatística: ANOVA de duas vias com teste Student-Newman-Keuls post hoc. P-valores <0,05 foram considerados significativos.

Resultados

O óleo de copaíba reduziu a resistência vascular pulmonar e a hipertrofia do ventrículo direito (VD) hipertrofia (Índice de Fulton (mg/mg)): MCT-O= 0,39±0,03; MCT= 0,49±0,01), e função sistólica melhorada (fração de encurtamento do VD, %) no grupo MCT-O (17,8±8,2) em comparação com o grupo de MCT (9,4±3,1; p<0,05). Além disso, no grupo MCT-O, espécies reativas do oxigênio e os níveis de carbonila foram reduzidos, e os parâmetros antioxidantes aumentaram no sangue periférico (p <0,05).

Conclusões

Os resultados deste estudo sugerem que o óleo de copaíba tem um efeito antioxidante sistêmico interessante, que se reflete na melhoria da função e na morfometria do VD nesse modelo de Cor pulmonale . A atenuação do Cor pulmonale promovida pelo óleo de copaíba coincidiu com uma redução no stress oxidativo sistêmico.

Updated knowledge and practical implementations of stress echocardiography in ischemic and non-ischemic cardiac diseases: an expert consensus of the Working Group of Echocardiography of the Hellenic Society of Cardiology

Stress echocardiography (SE) is a well-established and valid technique, widely-used for the diagnostic evaluation of patients with ischemic and non-ischemic cardiac diseases. This statement of the Echocardiography Working Group of the Hellenic Society of Cardiology summarizes the consensus of the writing group regarding the applications of SE, based on the expertise of their members and on a critical review of current medical literature. The main objectives of the consensus document include a comprehensive review of SE methodology and training, focusing on the preparation, the protocols used and the analysis of the SE images and an updated, evidence-based knowledge about SE applications on ischemic and non-ischemic heart diseases, such as in cardiomyopathies, heart failure and valvular heart disease.

Bilateral Subarachnoid Hemorrhage and Bilateral Intracranial Hemorrhage With Reversible Cardiomyopathy During Dobutamine Stress Echocardiography

Dobutamine stress echocardiogram (DSE) is routinely used in the clinical assessment of patients with known or suspected coronary artery disease (CAD). DSE can cause serious complications including cerebrovascular accident (CVA). Even though the incidence of CVA associated with DSE is very low (<0.01%),it can be life-threatening or cause significant morbidity. We present a patient who developed acute multifocal intracranial hemorrhage (ICH) and subarachnoid hemorrhage (SAH) during the DSE. 

A 39-year-old female with no prior cardiac history presented to the outpatient echocardiography lab for DSE. She had a blunted heart rate response with increasing dose of dobutamine 30 μg/kg/min and was given one milligram of atropine. The patient complained of frontal headache, nausea, and severe dyspnea. Computed tomography head showed acute multifocal bilateral SAH, and left frontal and right parieto-occipital ICH. 

Hypertension is one of the risk factors for ICH and dobutamine infusion can exacerbate severe acute hypertension, which can cause acute intraparenchymal hemorrhage. Even though the risk of ICH associated with DSE is extremely low, there should be increased vigilance if there is development of severe acute hypertension, and the operator should keep a low threshold for further evaluation if the patient develops neurological symptoms.

Stress cardiomyopathy induced during dobutamine stress echocardiography

Background

Catecholamines play a central role in pathogenesis of stress cardiomyopathy (SC). We aimed to review the clinical characteristics, procedural details and outcomes of patients with SC during dobutamine stress echocardiography (DSE).

Methods/Results

A total of 20 adults [age 64±15 years, 80% women, 67% hypertension, 20% diabetes, 33% hypercholesterolemia, 19% chronic kidney disease, 13% known anxiety disorder] with SC during DSE were identified from local digital archives of our laboratory (n=3) or reports in English literature (n=17). Indication for DSE was suspected coronary artery disease (CAD) in all patients. Left ventricular (LV) ejection fraction was normal at baseline. SC developed at a blood pressure of 154±47/86±24 mmHg, heart rate of 130±17 bpm (88±10% predicted maximum) and peak rate-pressure product of 20559±3898 mmHg*bpm. ST segment elevation was seen in 65%. SC occurred at peak dobutamine infusion rate of 38±6 μg/kg/min in 85% and during recovery in 15%. Atropine [0.7±0.6 (0.25-2) mg] was given to 7 patients. LV ejection fraction dropped to 30±6% with apical (40%), apical and mid (45%) or basal and mid (10%) circumferential LV ballooning. One patient (5%) had a mixed pattern of wall motion abnormality. LV outflow tract obstruction developed in 15%. Major adverse cardiac events occurred in 7 (35%) and included death (n=1), congestive heart failure (n=2), hypotension (n=3) and atrial fibrillation with heart failure (n=1). At a mean follow up duration of 19±19 days, complete or partial recovery of LV wall motion abnormality was seen in 18 and 1 patient, respectively.

Conclusion

SC uncommonly occurs during DSE. However, death and other adverse events (hypotension, heart failure and atrial fibrillation) may occur and require urgent attention. Once managed, complete recovery is expected in most patients.

Frequency of hypertensive response to dobutamine stress and diminished diagnostic value in patients with end-stage renal disease awaiting renal transplant

BACKGROUND

Patients with end-stage renal disease (ESRD) have a cardiovascular mortality about 15-30 times the general population and this is reduced by about 70% with renal transplant. Dobutamine stress echocardiography (DSE) is commonly performed for preoperative cardiac evaluation before renal transplantation. Hypertensive response during DSE occurs in about 1%-5% of DSE studies. However, it seems to be more frequent in patients with ESRD. But its frequency and clinical implications are not known.

METHODS AND RESULTS

Of the 249-consecutive adult ESRD patients undergoing DSE for pre-kidney transplant cardiac risk assessment at our dedicated clinic, 53 (21%) had a hypertensive response. Half of the patients with a hypertensive response had stress-induced segmental wall motion abnormalities, of whom only half had angiographically significant coronary artery disease by quantitative coronary angiography. The hypertensive response was not a predictor of survival. Stress-induced segmental wall motion abnormalities predicted poor survival in those with a normotensive response, but not in those with a hypertensive response. The main and independent predictor of a hypertensive response was higher baseline systolic blood pressure (P < .0001).

CONCLUSIONS

Hypertensive response to dobutamine stress is common in ESRD patients and is not a predictor of survival. Stress-induced segmental wall motion abnormalities occur nearly thrice as frequently with a hypertensive response, but this is a poor predictor of angiographically significant coronary artery disease and does not predict survival.

Bezold–Jarisch reflex-mediated asystole during dobutamine stress testing: a case report

Background

The Bezold–Jarisch reflex (BJR) is a cardioinhibitory parasympathetic response to activation of ventricular mechanoreceptors, which can result in bradycardia, atrioventricular block, or asystole. This phenomenon has been triggered by acute myocardial ischaemia, intra-arterial nitroglycerine use, natriuretic peptides, and with exceptional rarity, in middle-aged women only, by dobutamine infusion during stress echocardiography.

Case summary

We present the case of a 61-year-old woman who suffered a 5.1-s sinus pause during her 20 μg/kg/min infusion of dobutamine. Recovery was immediate following termination of dobutamine infusion. Concurrent echocardiography was normal, and subsequent cardiac catheterization and electrophysiologic study were normal.

Discussion

This is the fifth documented case of a severe BJR causing asystole during dobutamine infusion, which adds to the accumulating evidence supporting the benign nature of the condition.

Coronary Vasospasm After Dobutamine Stress Echocardiogram Triggered by Esmolol

Dobutamine stress echocardiography (DSE) is a commonly utilized method for coronary artery disease (CAD) diagnosis, and it provides important long-term prognostic information. We report a case of a 53-year-old female with multiple cardiovascular risk factors who underwent DSE for evaluation of underlying CAD. The examination was complicated by wide complex tachycardia and promoted administration of esmolol, which shortly led to ST-segment elevation myocardial infarction (STEMI). Coronary angiography showed complete absence of CAD. Coronary vasospasm was a possible suggested mechanism due to the pharmacologic interaction between beta-blockers and dobutamine on alpha- and beta-adrenergic receptors.

Coronary artery spasm following dobutamine stress echocardiogram

A 53-year-old woman with atypical chest pain underwent a dobutamine stress echocardiogram (DSE) and developed a coronary spasm (CS) with severe pain and dramatic ST-segment elevation 9 min after dobutamine infusion was discontinued. The spasm resolved after sublingual nitroglycerin administration. The same-day coronary angiogram showed non-significant stenosis in the three coronary territories. Retrospectively, we found that the patient had vasospastic angina (VSA), a condition that has been strongly associated with the development of dobutamine-induced CS. Mechanisms of dobutamine-induced CS are not fully understood and include endothelial dysfunction leading to deficient nitric oxide-mediated coronary vasodilation in response to increased myocardial oxygen demand as well as imbalance between β1 and β2 adrenergic effects of dobutamine. Dobutamine-induced CS has also been much more frequently reported in patients from Asian descent with VSA. VSA should be systemically recognised in patients considered for DSE and, if present, other modalities of stress imaging should be discussed.

Incidence and variables associated with arrhythmias during dobutamine-atropine stress echocardiography among patients with Chagas disease

BACKGROUND

Dobutamine stress echocardiography (DSE) is an important tool in the diagnosis of coronary artery disease. However, there is hesitation in clinical practice for using it in patients with Chagas disease (CD) due to the arrhythmogenic potential of this heart condition. This study aimed to evaluate the incidence and variables associated with arrhythmias during DSE in a population of patients with CD.

METHODS

A population of 205 consecutive patients with CD and suspected coronary heart disease was assessed through a retrospective database analysis. CD was confirmed in all patients by serological testing.

RESULTS

The mean age of the patients selected was 64 years, and 65.4% of the patients were female. Significant arrhythmias occurred as follows: nonsustained ventricular tachycardia in 7.3% of patients; supraventricular tachycardia and sustained ventricular tachycardia in 1%; and atrial fibrillation in 0.5%. Nonsignificant arrhythmias occurred as follows: premature ventricular contractions in 48% of patients and bigeminy in 4.4%. Values for the wall-motion score index at rest greater than 1.12 and 1.18 were independently correlated with the occurrence of nonsignificant arrhythmias (odds ratio [OR] = 2.90, P < 0.001) and significant arrhythmias (OR = 4.23, P = 0.044), respectively.

CONCLUSION

DSE should be considered a safe examination in patients with CD despite the known increased risk of arrhythmias in this group of patients. The occurrence of arrhythmias was low in this study. Abnormal wall-motion score index values at rest were associated with the occurrence of significant and nonsignificant arrhythmias during the test.

Localized rest and stress human cardiac creatine kinase reaction kinetics at 3 T

Changes in the kinetics of the creatine kinase (CK) shuttle are sensitive markers of cardiac energetics but are typically measured at rest and in the prone position. This study aims to measure CK kinetics during pharmacological stress at 3 T, with measurement in the supine position. A shorter "stressed saturation transfer" (StreST) extension to the triple repetition time saturation transfer (TRiST) method is proposed. We assess scanning in a supine position and validate the MR measurement against biopsy assay of CK activity. We report normal ranges of stress CK forward rate (kfCK ) for healthy volunteers and obese patients. TRiST measures kfCK in 40 min at 3 T. StreST extends the previously developed TRiST to also make a further kfCK measurement during <20 min of dobutamine stress. We test our TRiST implementation in skeletal muscle and myocardium in both prone and supine positions. We evaluate StreST in the myocardium of six healthy volunteers and 34 obese subjects. We validated MR-measured kfCK against biopsy assays of CK activity. TRiST kfCK values matched literature values in skeletal muscle (kfCK  = 0.25 ± 0.03 s-1 vs 0.27 ± 0.03 s-1 ) and myocardium when measured in the prone position (0.32 ± 0.15 s-1 ), but a significant difference was found for TRiST kfCK measured supine (0.24 ± 0.12 s-1 ). This difference was because of different respiratory- and cardiac-motion-induced B0 changes in the two positions. Using supine TRiST, cardiac kfCK values for normal-weight subjects were 0.15 ± 0.09 s-1 at rest and 0.17 ± 0.15 s-1 during stress. For obese subjects, kfCK was 0.16 ± 0.07 s-1 at rest and 0.17 ± 0.10 s-1 during stress. Rest myocardial kfCK and CK activity from LV biopsies of the same subjects correlated (R = 0.43, p = 0.03). We present an independent implementation of TRiST on the Siemens platform using a commercially available coil. Our extended StreST protocol enables cardiac kfCK to be measured during dobutamine-induced stress in the supine position.

A Modified Echocardiographic Classification of Mitral Valve Regurgitation Mechanism: The Role of Three-dimensional Echocardiography

In this report, we provide an overview of a new, updated echocardiographic classification of mitral regurgitation mechanisms to provide a more comprehensive and detailed assessment of mitral valve disorders. This is relevant to modern mitral valve repair techniques, with special attention to the added value of 3D-echocardiography.

Occurrence of Atrial Fibrillation During Dobutamine Stress Echocardiography

Dobutamine stress echocardiography (DSE) is a widely used examination for assessment of coronary ischemia, but several complications have been reported. The aim of this study was to assess the incidence of atrial fibrillation (AF) during DSE, and a systematic review and meta-analysis were also performed to determine an accurate estimate of the AF incidence. Over a 16-year period, we reviewed all patients referred for DSE. We systematically analyzed all ECG performed during DSE to detect AF during the examination. DSE was completely performed in 4,818 patients (mean age: 62.1 ± 11.7 years). AF was observed in 40 patients (31 men, mean age: 79.7 ± 8.9 years). Incidence of AF during DSE was 0.83%. Regarding the meta-analysis, the combined AF incidence was 0.86%. In our study, patients with AF occurrence had more frequent previous history of paroxysmal AF (p = 0.02) were also older (p < 0.0001) and incidence of AF during DSE increased with age: 0% below 60 years, 0.45% in patients 60 to 69 years, 1.3% in patients 70 to 79 years, and 4% in patients >80 years (p < 0.0001). In multivariate analysis, the factors significantly associated with an increased risk of AF were age (adjusted odds ratio (aOR) = 2.4, 95% confidence interval: 1.5 to 3.3, p = 0.003) and previous history of paroxysmal AF (aOR = 1.5, 95% confidence interval: 1.1 to 1.9; p = 0.04). In conclusion, AF is uncommon during DSE, and elderly patients and patients with previous history of paroxysmal AF are at risk of AF during DSE.

Low to Intermediate Dose Atropine Administration During Dobutamine Stress Echocardiography in the Pre-Liver Transplant Population

INTRODUCTION

Dobutamine stress echocardiography (DSE) is frequently used to screen for obstructive coronary artery disease in the pre-liver transplant evaluation. Although atropine is a commonly used adjunctive medication, no study has evaluated its side effect profile in patients with end-stage liver disease (ESLD).

RESEARCH QUESTION

What is the safety of atropine in candidates undergoing pre-liver transplant evaluation when atropine is used in stress testing?

DESIGN

This multicenter, prospective study enrolled patients over a 6-month period undergoing pre-liver transplant evaluation. Each patient completed a questionnaire assessing anticholinergic-related symptoms within 24 hours of testing and 48 hours following. Comparisons were made among patients receiving any atropine dose versus those who did not and among patients receiving at least 1 mg atropine and those receiving less/none.

RESULTS

Forty patients were evaluated, and 32 (80%) had adjunctive atropine administered. No differences in clinical characteristics were noted. In comparisons among patients receiving any dose of atropine with those who did not, questionnaire results indicated a higher rate of nausea prior to testing and higher overall symptom severity following testing in patients not receiving atropine. In comparisons among patients receiving less than 1 mg atropine with those receiving at least 1 mg atropine, no difference in pre- or posttesting questionnaire responses was present. No patient in the study required reversal agents or hospitalization within 7 days of testing.

CONCLUSIONS

Atropine, a hepatically metabolized medication, did not predispose patients with ESLD to an increased symptom burden, and clinical outcomes related to DSE were unaffected.

Safety and efficacy of physiologist-led dobutamine stress echocardiography: experience from a tertiary cardiac centre

Background

Dobutamine stress echocardiography (DSE) services have traditionally been medically led. In some UK institutions, DSE lists are led by physiologists with medical support. In our tertiary cardiac centre at New Cross Hospital (NCH), the DSE service was established by a consultant echocardiographer. Following intensive training and assessment, the Trust approved drug administration by named senior cardiac physiologists. We believe this is the first report of a cardiac physiologist-managed DSE service, including physiologist drug administration. We have assessed the feasibility, safety and validity of this physiologist-led DSE service.

Methods

Retrospective analysis of 333 patients undergoing stress echocardiogram for inducible reversible ischaemia, myocardial viability and valvular heart disease over 6 months. Patients’ case notes review after 18–24 months.

Results

Overall, 92% of all cases (306) were performed by physiologists. In 300 studies, dobutamine was administered. The majority of the referrals were for coronary artery disease (CAD) assessment (281). In 235 cases, the study was uncomplicated. Sixty-seven patients developed dobutamine-related side effects. In 16 cases, complications led to early termination of the study. In two cases, urgent medical review was needed. Of the 281 studies for CAD assessment, 239 were negative for ischaemia, 28 were positive and 14 inconclusive. In 5 out of 28 cases with echocardiogram, evidence of inducible ischaemia, coronary angiography revealed unobstructed coronary arteries.

Conclusion

This study demonstrates the safety and effectiveness of this practice and provides potential for the expansion of the physiologists’ role and physiologist-led DSE services in other hospitals.

Practical guidance for the implementation of stress echocardiography

Exercise stress testing has been widely undertaken for the diagnosis of heart diseases. The accurate assessment of clinical conditions can be conducted by comparing the findings obtained from the results of stress echocardiography with the changes in the blood/heart rate and electrocardiograms. Numerous overseas studies have reported the utility of stress echocardiography in diagnosing myocardial ischemia; in Japan, the use of this modality for this purpose was included in the national health insurance reimbursable list in 2012. Nevertheless, stress echocardiography is far from being a widespread practice in Japan. This might be due to insufficient equipment (e.g., ergometers, space for test implementation) at each medical institution, shortage of technicians and sonographers who are well experienced and who are responsible for obtaining images during stress testing. The other possible reasons include the limited evidence available in Japan and the lack of a standardized testing protocol. Further dissemination of the practice of exercise stress echocardiography in this country is deemed necessary to establish satisfactory evidence for the use of stress echocardiography in the Japanese population. To this end, efforts are underway to develop a standardized protocol and report format to be adopted throughout Japan. We here present a guideline created by the Guideline Development Committee of the Japanese Society of Echocardiography that describes safe and effective stress echocardiography protocols and report formats. The readers are encouraged to perform exercise stress echocardiography using the proposed template for consensus document and report attached to this guideline.

Atropine augments cardiac contractility by inhibiting cAMP-specific phosphodiesterase type 4

Atropine is a clinically relevant anticholinergic drug, which blocks inhibitory effects of the parasympathetic neurotransmitter acetylcholine on heart rate leading to tachycardia. However, many cardiac effects of atropine cannot be adequately explained solely by its antagonism at muscarinic receptors. In isolated mouse ventricular cardiomyocytes expressing a Förster resonance energy transfer (FRET)-based cAMP biosensor, we confirmed that atropine inhibited acetylcholine-induced decreases in cAMP. Unexpectedly, even in the absence of acetylcholine, after G-protein inactivation with pertussis toxin or in myocytes from M₂- or M_1/3-muscarinic receptor knockout mice, atropine increased cAMP levels that were pre-elevated with the β-adrenergic agonist isoproterenol. Using the FRET approach and in vitro phosphodiesterase (PDE) activity assays, we show that atropine acts as an allosteric PDE type 4 (PDE4) inhibitor. In human atrial myocardium and in both intact wildtype and M₂ or M_1/3-receptor knockout mouse Langendorff hearts, atropine led to increased contractility and heart rates, respectively. In vivo, the atropine-dependent prolongation of heart rate increase was blunted in PDE4D but not in wildtype or PDE4B knockout mice. We propose that inhibition of PDE4 by atropine accounts, at least in part, for the induction of tachycardia and the arrhythmogenic potency of this drug.

Feasibility of physiologist-led stress echocardiography for the assessment of coronary artery disease

BACKGROUND

Physiologist-led stress echocardiography (PLSE) services provide potential for expansion of SE services and increased productivity for cardiologists. There are however no published data on the feasibility of PLSE. We sought to assess the feasibility, safety and robustness of PLSE and cardiologist-led stress echocardiography (CLSE) for coronary artery disease (CAD) assessment.

METHODS

Retrospective analysis of 898 patients undergoing PLSE or CLSE for CAD assessment using exercise or dobutamine stress over 24 months. PLSE involved 2 cardiac physiologists (exercise) or 1 physiologist plus 1 cardiac nurse (dobutamine). A cardiology registrar was present in the echocardiography department during PLSE in case of medical complications. CLSE involved 1 physiologist and 1 trainee cardiologist who analysed the study and reviewed findings with an imaging cardiologist. Sixteen-segment wall motion scoring (WMS, WMSI) analysis was performed. Feasibility (stressor, image quality, proportion of completed studies, agreement with imaging cardiologist analysis) and safety (complication rate) were compared for PLSE and CLSE.

RESULTS

The majority of studies were CLSE (56.2%) and used dobutamine (68.7%). PLSE more commonly used exercise (69.2%). Overall, 96% of studies were successfully completed (>14 diagnostic segments in 98%, P = 0.899 PLSE vs CLSE). Commencement of PLSE was associated with an increase in annual SE's performed for CAD assessment. Complication rates were comparably very low for PLSE and CLSE (0.8% vs 1.8%, P = 0.187). There was excellent agreement between PLSE and CLSE WMS interpretation of 480 myocardial segments at rest (κ = 0.87) and stress (κ = 0.70) and WMSI (ICCs and Pearson's r >0.90, zero Bland-Altman mean bias).

CONCLUSION

This to our knowledge is the first study of the feasibility of PLSE. PLSE performed by well-trained physiologists is feasible and safe in contemporary practice. PLSE and CLSE interpretation of stress echocardiography for CAD agree very closely.

Ischemic heart disease and rheumatoid arthritis: Do inflammatory cytokines have a role?

BACKGROUND

The increase in Rheumatoid arthritis (RA) associated mortality is predominantly due to accelerated coronary artery and cerebrovascular atherosclerosis with increased risk of ischemic heart disease about 50% in RA patients compared to controls.

OBJECTIVE

To study the pathogenesis of ischemic heart disease in RA, role of inflammatory cytokine interplay, disease activity and rheumatoid factor positivity.

METHODS

Eighty RA patients and 44 healthy controls were included. All subjects were younger than 45years for females and 55years for males with exclusion of all traditional risk factors for atherosclerosis. Interleukin (IL) 1, 6 and 18 were assessed in all subjects. RA patients fulfilled ACR/EULAR 2010 criteria and were subjected to Dobutaminestress-echocardiography, diseases activity assessed by DAS-28, X-ray hands for Larsen score and function assessment by HAQ.

RESULTS

RA patients had significantly higher serum IL 1, 6 and 18 than controls (p=0.00 in all). Thirty four (42.5%) patients had hypertensive reaction on Dobutamine-stress-echocardiography, four of them had ischemic change, and 46 (57.5%) had normal reaction. All patients with hypertensive reaction had positive RF (p=0.00), 10 had DAS-28>5.1, 20 had DAS-28 from 3.2 to5.1 and 4 were in remission (p=0.001). CRP was higher in patients with hypertensive reaction (p=0.003) while serum levels of IL1, 6 and 18 showed no significant difference. In all patients, serum levels of IL1, 6 and 18 showed significant positive correlation with VAS, HAQ and DAS-28 (p<0.001 in all). Only IL18 showed significant positive correlation with X-ray score in all patients.

CONCLUSION

Disease activity and RF positivity play an important risk factor for ischemic heart disease in RA. Serum levels of IL1, 6 and 18 did not help much in detecting patients at risk of ischemic heart disease. Better control of RA disease activity with early remission helps in preventing cardiac complications. More studies on larger number of patients are needed for better understanding of mechanism of ischemic heart disease in RA.

Predictors and prognostic significance of atrial fibrillation developed during dobutamine stress echocardiography: A propensity score-matched comparison

AIMS

Atrial fibrillation (AF) uncommonly occurs during dobutamine stress echocardiography (DSE). We aimed to characterize the predictors and long-term prognostic significance of AF during DSE.

METHODS

The clinical, echocardiographic, and outcome data of patients in sinus rhythm who developed AF during DSE were reviewed and compared to a propensity score-matched group of controls.

RESULTS

Atrial fibrillation developed in 73 (1% of 7026) patients (age 70±10 years, 58% men). Compared to 144 propensity score-matched controls without AF during DSE, those with AF were more likely to have had history of prior AF (23% vs 8%, P=.002), known coronary artery disease (CAD; 22% vs 10%, P=.037), enlarged left ventricle (LV; 27% vs 9%, P=.002), LV wall-motion abnormality (33% vs 12%, P<.0001), enlarged aortic root (22% vs 8%, P=.009), or dilated left atrium (52% vs 30%, P=.002). Multivariate logistic regression analysis identified prior history of AF (OR=3.7, 95% CI 1.5-9.0, P=.005), larger LV size (OR=3.1, 95% CI 1.3-7.3, P=.009), and lower LV ejection fraction (OR=-0.95, 95% CI -0.92 to -0.99, P=.02) as independent predictors of AF during DSE. At a mean follow-up period of 3.4 (0.5-7.3) years, those with AF during DSE were more likely to develop new coronary events (22% vs 10%, P=.0372), new-onset heart failure (19% vs 4%, P=.0003), or die from any cause (27% vs 6%, P<.0001). Kaplan-Meier curves demonstrated significantly lower event-free survival in patients compared to controls (P by log-rank test=.001) over the follow-up period.

CONCLUSION

Dobutamine-induced AF occurs more commonly in those with prior history of AF and remodeled LV and is associated with unfavorable outcomes.

L, Rassi S. Dobutamine Stress Echocardiography Safety in Chagas Disease Patients

BACKGROUND:

A few decades ago, patients with Chagas disease were predominantly rural workers, with a low risk profile for obstructive coronary artery disease (CAD). As urbanization has increased, they became exposed to the same risk factors for CAD of uninfected individuals. Dobutamine stress echocardiography (DSE) has proven to be an important tool in CAD diagnosis. Despite being a potentially arrhythmogenic method, it is safe for coronary patients without Chagas disease. For Chagas disease patients, however, the indication of DSE in clinical practice is uncertain, because of the arrhythmogenic potential of that heart disease.

OBJECTIVES:

To assess DSE safety in Chagas disease patients with clinical suspicion of CAD, as well as the incidence of arrhythmias and adverse events during the exam.

METHODS:

Retrospective analysis of a database of patients referred for DSE from May/2012 to February/2015. This study assessed 205 consecutive patients with Chagas disease suspected of having CAD. All of them had their serology for Chagas disease confirmed.

RESULTS:

Their mean age was 64±10 years and most patients were females (65.4%). No patient had significant adverse events, such as acute myocardial infarction, ventricular fibrillation, asystole, stroke, cardiac rupture and death. Regarding arrhythmias, ventricular extrasystoles occurred in 48% of patients, and non-sustained ventricular tachycardia in 7.3%.

CONCLUSION:

DSE proved to be safe in this population of Chagas disease patients, in which no potentially life-threatening outcome was found.

FUNDAMENTO:

Até poucas décadas atrás, os pacientes chagásicos eram predominantemente trabalhadores rurais, com baixo perfil de risco para doença obstrutiva coronária. Com a crescente urbanização, passaram a ter os mesmos fatores de risco para doença aterosclerótica que indivíduos não infectados. O ecocardiograma sob estresse com dobutamina (EED) é uma importante ferramenta no diagnóstico de coronariopatia. É referido, porém, como um método potencialmente arritmogênico, mas seguro, em pacientes coronarianos não chagásicos. Entretanto, há insegurança na prática clínica de indicá-lo no paciente chagásico, devido ao potencial arritmogênico já intrínseco nesta cardiopatia.

OBJETIVOS:

Analisar a segurança do EED em uma população de chagásicos com suspeita clínica de coronariopatia.

MÉTODOS:

Análise retrospectiva de um banco de dados de pacientes encaminhados para a realização do EED entre maio/2012 e fevereiro/2015. Avaliou-se pacientes consecutivos portadores de doença de Chagas e com suspeita de coronariopatia. Confirmou-se a sorologia para doença de Chagas em todos os pacientes.

RESULTADOS:

A média etária dos 205 pacientes analisados foi de 64 ± 10 anos, sendo a maioria do sexo feminino (65,4%). Nenhum paciente apresentou eventos adversos significativos, como infarto agudo do miocárdio, fibrilação ventricular, assistolia, acidente vascular encefálico, ruptura cardíaca ou morte. Quanto às arritmias, extrassístoles ventriculares frequentes ocorreram em 48% dos pacientes, taquicardia ventricular não sustentada em 7,3%, bigeminismo em 4,4%, taquicardia supraventricular e taquicardia ventricular sustentada em 1% e fibrilação atrial em 0,5%.

CONCLUSÃO:

O EED mostrou ser um exame seguro nessa população de pacientes chagásicos, onde nenhum desfecho grave foi encontrado.

The prognostic role of stress echocardiography in a contemporary population and the clinical significance of limited apical ischaemia

INTRODUCTION

In this study, we aim to reassess the prognostic value of stress echocardiography (SE) in a contemporary population and to evaluate the clinical significance of limited apical ischaemia, which has not been previously studied.

METHODS

We included 880 patients who underwent SE. Follow-up data with regards to MACCE (cardiac death, myocardial infarction, any repeat revascularisation and cerebrovascular accident) were collected over 12 months after the SE. Mortality data were recorded over 27.02 ± 4.6 months (5.5-34.2 months). We sought to investigate the predictors of MACCE and all-cause mortality.

RESULTS

In a multivariable analysis, only the positive result of SE was predictive of MACCE (HR, 3.71; P = 0.012). The positive SE group was divided into 2 subgroups: (a) inducible ischaemia limited to the apical segments ('apical ischaemia') and (b) ischaemia in any other segments with or without apical involvement ('other positive'). The subgroup of patients with apical ischaemia had a significantly worse outcome compared to the patients with a negative SE (HR, 3.68; P = 0.041) but a similar outcome to the 'other positive' subgroup. However, when investigated with invasive coronary angiography, the prevalence of coronary artery disease (CAD) and their rate of revascularisation was considerably lower. Only age (HR, 1.07; P < 0.001) was correlated with all-cause mortality.

CONCLUSION

SE remains a strong predictor of patients' outcome in a contemporary population. A positive SE result was the only predictor of 12-month MACCE. The subgroup of patients with limited apical ischaemia have similar outcome to patients with ischaemia in other segments despite a lower prevalence of CAD and a lower revascularisation rate.

[Prethrombus acute constitution during dobutamine stress echocardiography]

Although generally regarded as a safe stress modality, dobutamine stress echocardiography (DSE) has been associated with several well described complications. However, to our knowledge, acute constitution of thrombi during the stress test has never been described. In this report, we present the case of a 64 year-old man with a history of ischemic heart disease who underwent a preoperative DSE; during the test, we witnessed a striking acute constitution of an intense prethrombotic state with almost a formation of a highly mobile massive thrombus adjacent to the infero-apical segment spontaneously resolving few minutes after the end of the test.

Impact of Early Coronary Revascularization on Long-Term Outcomes in Patients With Myocardial Ischemia on Dobutamine Stress Echocardiography

The role of early coronary revascularization in the management of stable coronary artery disease remains controversial. The aim of this study was to evaluate the impact of early coronary revascularization on long-term outcomes (>10 years) after an ischemic dobutamine stress echocardiography (DSE) in patients with known or suspected coronary artery disease. Patients without stress-induced ischemia on DSE and those who underwent late coronary revascularization (>90 days after DSE) were excluded. The final study cohort consisted of 905 patients. A DSE with a peak wall motion score index of 1.1 to 1.7 was considered mild to moderately abnormal (n = 460), and >1.7 was markedly abnormal (n = 445). End points were all-cause and cardiac mortality. The impact of early coronary revascularization on outcomes was assessed using Kaplan-Meier survival analysis and Cox's proportional hazard regression models. Early coronary revascularization was performed in 222 patients (percutaneous coronary intervention in 113 [51%] and coronary artery bypass grafting in 109 patients [49%]). During a median follow-up time of 10 years (range 8 to 15), 474 deaths (52%) occurred, of which were 241 (51%) due to cardiac causes. Kaplan-Meier survival curves showed that both in patients with a markedly abnormal DSE and a mild-to-moderately abnormal DSE, early revascularization was associated with better long-term outcomes. Multivariable analyses revealed that early revascularization had a beneficial effect on all-cause mortality (hazard ratio 0.60, 95% confidence interval 0.46 to 0.79) and cardiac mortality (hazard ratio 0.49, 95% confidence interval 0.34 to 0.72). In conclusion, early coronary revascularization has a beneficial impact on long-term outcomes in patients with myocardial ischemia on DSE. Early coronary revascularization was associated with better outcomes not only in patients with a markedly abnormal DSE but also in those with a mild to moderately abnormal DSE.

Incidence, Characteristics, Risk Factors, and Outcomes of Takotsubo Cardiomyopathy With and Without Ventricular Arrhythmia

Takotsubo cardiomyopathy (TC) is a medical entity mimicking an acute coronary syndrome (ACS). Ventricular arrhythmia (VA) in TC has been reported in small studies, leading to uncertain knowledge of its incidence. We sought to describe the characteristics, incidence, predictive factors, and outcomes of VA in patients presenting with TC. Over a 12-year period, we reviewed all patients (n = 5,484) referred to our coronary care unit for a suspicion of ACS. TC was diagnosed in 90 patients according to the Mayo Clinic criteria. Incidence of VA among TC was 10%. In multivariate analysis, the factors significantly associated with an increased risk of VA were syncope (p = 0.007), age <55 years (p = 0.008), atypical TC (p = 0.04), a troponin I peak >7 μg/L (p = 0.04), and dobutamine use during hospitalization (p = 0.04). During follow-up, there was no significant difference in mortality rate between patients with or without VA. In conclusion, VA occurred in 10% of patients at the acute phase of TC and independent predictive factors of VA were syncope, atypical pattern of TC, high troponin peak, dobutamine use, and a relatively young age in a female and menopausal population. During the acute phase, identification of high-risk patients with VA allows better management, with electrocardiographic monitoring and therapeutic intervention in the coronary care unit.

Comparison of Hyperemic Impedance Echocardiography with Dobutamine Stress Echocardiography to Detect Inducible Myocardial Ischemia: A Pilot Study

BACKGROUND

Stress echocardiography using exercise or pharmacological stressors is either contraindicated or associated with significant side effects in some patients. This pilot study was designed to evaluate a new technique, hyperemic impedance echocardiography (HIE). It is based on reactive coronary hyperemia when transient limb ischemia is induced by tourniquet inflation. We hypothesized that this physiologic coronary hyperemia can identify inducible myocardial ischemia by assessment of regional wall motion abnormalities on echocardiography when compared with dobutamine stress echocardiography (DSE).

METHODS

Twenty consecutive outpatients with suspected stable coronary artery disease (CAD) who underwent clinically indicated DSE were recruited for performance of HIE after informed consent was obtained. Standard graded dobutamine infusion protocol from 5 to 40 μg/kg per min was used for DSE. HIE was performed by inflating tourniquets at a pressure of 10 mmHg below the systolic blood pressure for 1 minute in three of four extremities at a time for total of four cycles. Echocardiography was performed immediately after the last rotating tourniquet deflation. DSE and HIE were classified as abnormal for development of new or worsening wall motion abnormality in at least one myocardial segment. Test characteristics were also determined for a subset of these patients (n = 12) who underwent clinically indicated coronary angiography.

RESULTS

Hyperemic impedance echocardiography showed 86% sensitivity, 67% specificity, 86% positive predictive value, and 67% negative predictive value with a test accuracy of 80% to detect inducible myocardial wall motion abnormalities when compared with DSE. HIE also showed 83% sensitivity, 75% negative predictive value with a test accuracy of 66.7% for detection of significant (≥50% diameter stenosis) CAD on coronary angiography.

CONCLUSION

In this pilot study, HIE was a feasible, safe, and promising method for detection of inducible myocardial ischemia by assessment of regional wall motion abnormalities when compared to DSE and coronary angiography. Larger studies are needed to confirm these findings.

A Heart Stopping Case of the Bezold-Jarisch Reflex

The Bezold-Jarisch reflex is a parasympathetic reflex induced by intense mechanical stimulation of the ventricular myocytes. Exceptionally, cases have been described in patients receiving dobutamine infusion during a stress echocardiography. All were healthy middle-aged women and recovered without sequelae. A healthy 60-year-old woman suffered two 5.9-second episodes of asystole during her 20 mcg/kg/min infusion of dobutamine. Recovery was quick and without sequelae. Echocardiography and coronary angiography were both normal. In conclusion, this is the fourth documented case of a severe Bezold-Jarisch reflex causing asystole during dobutamine infusion. Diagnosis can only be made after excluding all other possible diagnoses, most importantly ischemia. This serves as a reminder of the importance of close monitoring during dobutamine infusion.

Cardiac imaging and functional assessment in pregnancy

There are multiple imaging modalities available for the assessment of pregnant women with known or suspected cardiac disease. Because of its safety and general availability, echocardiography is the preferred study of choice for the evaluation of ventricular function, valvular heart disease, congenital heart disease, evaluation of the aorta, and the estimation of cardiac hemodynamics in a pregnant patient. Cardiac MRI can be performed, especially for diseases of the aorta and complex congenital heart disease. Radiation exposure for the fetus and the mother will be discussed in the use of CT angiography, nuclear imaging, and left-heart catheterization including coronary angiography for specific indications in the pregnant woman. The use of exercise testing during pregnancy for functional assessment will be presented.

Intraparenchymal haemorrhage and uncal herniation resulting from dobutamine stress echocardiography

Intracranial haemorrhage (ICH) resulting from dobutamine stress echocardiography (DSE) is a rare complication in an otherwise relatively safe procedure. There has been one previously reported case of ICH associated with DSE in a patient who was fully anticoagulated. The authors report a second case of ICH associated with DSE leading to a poor outcome. Unlike the previous report, this patient was not fully anticoagulated and bleeding resulted from uncontrolled hypertension. Clinicians should be attentive to the risk of ICH associated with DSE in the setting of uncontrolled hypertension.

Coronary flow velocity reserve during dobutamine stress echocardiography

BACKGROUND

A coronary flow velocity reserve (CFVR)≥2 is adequate to infer a favorable prognosis or the absence of significant coronary artery disease.

OBJECTIVE

To identify parameters which are relevant to obtain CFVR (adequate or inadequate) in the left anterior descending coronary artery (LAD) during dobutamine stress echocardiography (DSE).

METHODS

100 patients referred for detection of myocardial ischemia by DSE were evaluated; they were instructed to discontinue the use of β-blockers 72 hours prior to the test. CFVR was calculated as a ratio of the diastolic peak velocity (cm/s) (DPV) on DSE (DPV-DSE) to baseline DPV at rest (DPV-Rest). In group I, CFVR was <2 and, in group II, CFVR was ≥2. The Fisher's exact test and Student's t test were used for the statistical analyses. P values<0.05 were considered statistically significant.

RESULTS

At rest, the time (in seconds) to obtain Doppler in LAD in groups I and II was not different (53±31 vs. 45±32; p=0.23). During DSE, LAD was recorded in 92 patients. Group I patients were older (65.9±9.3 vs. 61.2±10.8 years; p=0.04), had lower ejection fraction (61±10 vs. 66±6%; p=0.005), higher DPV-Rest (36.81±08 vs. 25.63±06 cm/s; p<0.0001) and lower CFVR (1.67±0.24 vs. 2.53±0.57; p<0.0001), but no difference was observed regarding DPVDSE (61.40±16 vs. 64.23±16 cm/s; p=0.42). β-blocker discontinuation was associated with a 4-fold higher chance of a CFVR<2 (OR= 4; 95% CI [1.171-13.63], p=0.027).

CONCLUSION

DPV-Rest was the main parameter to determine an adequate CFVR. β-blocker discontinuation was significantly associated with inadequate CFVR. The high feasibility and the time to record the LAD corroborate the use of this methodology.

Rationale and design of a randomized trial comparing initial stress echocardiography versus coronary CT angiography in low-to-intermediate risk emergency department patients with chest pain

BACKGROUND

Comparative effectiveness research (CER) has become a major focus of cardiovascular disease investigation to optimize diagnosis and treatment paradigms and decrease healthcare expenditures. Acute chest pain is a highly prevalent reason for evaluation in the Emergency Department (ED) that results in hospital admission for many patients and excess expense. Improvement in noninvasive diagnostic algorithms can potentially reduce unnecessary admissions.

OBJECTIVE

To compare the performance of treadmill stress echocardiography (SE) and coronary computed tomography angiography (CTA) in ED chest pain patients with low-to-intermediate risk of significant coronary artery disease.

DESIGN

This is a single-center, randomized controlled trial (RCT) comparing SE and CTA head-to-head as the initial noninvasive imaging modality. The primary outcome measured is the incidence of hospitalization. The study is powered to detect a reduction in admissions from 28% to 15% with a sample size of 400. Secondary outcomes include length of stay in the ED/hospital and estimated cost of care. Safety outcomes include subsequent visits to the ED and hospitalizations, as well as major adverse cardiovascular events at 30 days and 1 year. Patients who do not meet study criteria or do not consent for randomization are offered entry into an observational registry.

CONCLUSIONS

This RCT will add to our understanding of the roles of different imaging modalities in triaging patients with suspected angina. It will increase the CER evidence base comparing SE and CTA and provide insight into potential benefits and limitations of appropriate use of treadmill SE in the ED.