Dynamic Left Ventricular Outflow Tract Obstruction in Acute Myocardial Infarction With Shock

The Role of Focused 2-Dimensional Echocardiography in Managing Left Ventricular Outflow Tract Obstruction Mimicking Cardiogenic Shock

Left ventricular outflow tract obstruction (LVOTO) is a common cardiogenic shock (CS) mimic. We present 3 cases of patients presenting with CS following myocardial infarction, exhibiting a poor response to conventional treatment with inotropy and mechanical circulatory support. This triggered echocardiographic assessment by critical care physicians using focused 2-dimensional (2D) echocardiography. This timely assessment identified anterior mitral valve leaflet entrainment into the left ventricular outflow tract (LVOT), causing LVOTO as the underlying shock mechanism. Echocardiographic findings have led to significant changes in management. The patients underwent fluid administration, weaning from inotropy, and mechanical circulatory support explantation, leading to relief of LVOTO and improved hemodynamics. Critical care basic 2D echocardiography accreditations focus on myocardial function and pericardial effusions. Relevant societies administering these accreditations should consider adding LVOT assessment to enable timely diagnosis of this life-threatening CS mimic.

Acquired Dynamic Left Ventricular Outflow Tract Obstruction: A Rare Complication of Acute Myocardial Infarction

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Reversible outflow tract obstruction is a rare complication of myocardial infarction.

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Immediate bedside echocardiogram can help recognize this complication.

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Sigmoid-shaped septum and narrow aortoseptal angle are likely anatomic contributors.

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Tachycardia, hypertension, and basal hypercontractility are hemodynamic factors.

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Early beta-blockers and revascularization can reverse this complication.

A case report of cardiogenic shock from takotsubo cardiomyopathy with left ventricular outflow tract obstruction: fundamental lessons in cardiac pathophysiology

Background

A subset of patients with takotsubo cardiomyopathy will develop significant dynamic left ventricular outflow tract (LVOT) obstruction leading to cardiogenic shock. However, traditional therapies for cardiogenic shock that focus on increased inotropy and afterload reduction can be detrimental in this situation.

Case summary

We describe a 71-year-old woman who presented to the emergency department with typical, substernal chest pain found to be hypotensive with ST-elevations in the lateral leads. Coronary angiography showed no significant coronary artery disease, but a left ventriculogram demonstrated takotsubo cardiomyopathy. Right heart catheterization revealed cardiogenic shock and elevated filling pressures. Haemodynamics and symptoms worsened with the initiation of dopamine and placement of intra-aortic balloon pump but improved with the initiation of phenylephrine. Follow-up echocardiogram demonstrated dynamic LVOT obstruction with concomitant severe mitral regurgitation (MR). The patient recovered in the intensive care unit for 5 days after successful weaning of phenylephrine and initiation of low-dose beta-blocker. Repeat echocardiogram 3 weeks later showed complete resolution of apical akinesis, LVOT obstruction, and MR.

Discussion

Elucidating whether dynamic LVOT obstruction is contributing to cardiogenic shock physiology is paramount since the management radically differs depending on the presence or absence of obstruction. Corrective therapy focuses on reducing the LVOT gradient and includes fluid administration to improve preload, beta-blocker therapy to increase diastolic filling time, and vasopressors to raise afterload.

Transient Systolic Anterior Motion of the Anterior Mitral Valve Leaflet in a Critical Care Patient with a Structurally Normal Heart

Systolic anterior motion (SAM) is defined as the displacement of the anterior mitral leaflet towards the left ventricular outflow tract, which results in left ventricular outflow tract obstruction (LVOTO). The SAM of the anterior mitral leaflet is a well-established phenomenon in hypertrophic obstructive cardiomyopathy (HOCM), but its occurrence in a structurally healthy heart is uncommon. We present a critical care patient with presumed septic shock whose blood pressure was previously controlled by fluid resuscitation and vasopressors. He developed a new cardiac murmur along with hypotension despite being on vasopressors. The echocardiographic assessment revealed no structural heart disease or valvular vegetations but a hyperdynamic left ventricle with significant SAM of the anterior mitral leaflet, resulting in mitral regurgitation (MR). The murmur and hypovolemia resolved after aggressive fluid resuscitation and by decreasing the vasopressor dose.

A case report: haemodynamic instability due to true dynamic left ventricular outflow tract obstruction and systolic anterior motion following resuscitation: reversal of haemodynamics on supportive veno-arterial extracorporeal membrane oxygenation

Background

Obstruction of the left ventricular outflow tract (LVOT) as seen in hypertrophic cardiomyopathy is a dynamic condition with a wide range of clinical presentations and symptoms.

Case summary

We report the use of veno-arterial extracorporeal membrane oxygenation in a female patient who was resuscitated after out-of-hospital cardiac arrest. Soon after admission the patient developed critical haemodynamic compromise due to severe obstruction of the left ventricle outflow tract and systolic anterior motion (SAM) of the mitral valve. Veno-arterial extracorporeal membrane oxygenation restored haemodynamics and was weaned after 4 days without any haemodynamic compromise due to SAM. The patient was discharged from the intensive care unit at Day 13, and after 3 days at the coronary care unit, she was discharged to ambulatory follow-up with no sequelae.

Discussion

Veno-arterial extracorporeal membrane oxygenation restored haemodynamic stability in this patient with dynamic severe LVOT obstruction following cardiac arrest.

Management of systolic anterior motion of the mitral valve: a mechanism-based approach

Although the mechanism of systolic anterior motion (SAM) of the mitral valve is unknown, it is known to have a multifactorial pathophysiology. Echocardiographic analysis of the mitral leaflet revealed the step-wise progression of SAM, and intraventricular flow analysis revealed the contribution of drag force generated by the misled flow below the posterior leaflet. Although several diverse clinical features of SAM are already known, some key features need to be abstracted from among them to understand the regulation of SAM establishment. This paper reviews past articles that have investigated the mechanism of SAM and proposes a mechanism-based concept to provide insights for better comprehension of SAM recognition.

Cardiogenic Shock Secondary to Takotsubo Cardiomyopathy in a Patient with Preexisting Hypertrophic Obstructive Cardiomyopathy

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Echocardiography is used to diagnose hypertrophic obstructive cardiomyopathy (HOCM) and Takotsubo cardiomyopathy (TCM).

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Hypotension in a patient with TCM should be evaluated for left ventricular outflow tract obstruction (LVOTO).

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Management of TCM is challenging in patients with HOCM with severe LVOTO.

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Hypotension in LVOTO may paradoxically worsen with standard intravenous inotropes.

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Fluid resuscitation, beta-blockers, alpha agonists, and intra-aortic balloon pump are the treatment options in LVOTO.

Hypertrophic Cardiomyopathy and Left Ventricular Outflow Tract Obstruction: Expecting the Unexpected

Hypertrophic cardiomyopathy is an increasingly recognized clinical disease that carries perioperative risk. Patients may or may not carry a preoperative diagnosis, but provocable left ventricular outflow tract gradients place them at risk for hemodynamic compromise under surgical conditions. Early recognition of obstructive patterns and rapid management alterations in the face of instability are imperative for the treatment of these patients. This review focuses on the diagnostic criteria, risk factors, and management strategies for the perioperative hypertrophic cardiomyopathy patient. Finally, novel diagnostic modalities are discussed.

Expert consensus document: Echocardiography and lung ultrasonography for the assessment and management of acute heart failure

Echocardiography is increasingly recommended for the diagnosis and assessment of patients with severe cardiac disease, including acute heart failure. Although previously considered to be within the realm of cardiologists, the development of ultrasonography technology has led to the adoption of echocardiography by acute care clinicians across a range of specialties. Data from echocardiography and lung ultrasonography can be used to improve diagnostic accuracy, guide and monitor the response to interventions, and communicate important prognostic information in patients with acute heart failure. However, without the appropriate skills and a good understanding of ultrasonography, its wider application to the most acutely unwell patients can have substantial pitfalls. This Consensus Statement, prepared by the Acute Heart Failure Study Group of the ESC Acute Cardiovascular Care Association, reviews the existing and potential roles of echocardiography and lung ultrasonography in the assessment and management of patients with acute heart failure, highlighting the differences from established practice where relevant.

Stress cardiomyopathy of the critically ill: Spectrum of secondary, global, probable and subclinical forms

Stress cardiomyopathy (SC) typically presents as potential acute coronary syndrome (ACS) in previously healthy people. While there may be physical or mental stressors, the initial symptom is usually chest pain. This form conforms to the published Mayo diagnostic criteria, is well reported and as the presentation is initially cardiac, is considered primary SC. Increasingly we see SC develop several days into the hospitalization secondary to medical or surgical critical illness. This condition is more complex, presents atypically, is not easy to recognize and carries a much worse prognosis. Label of Secondary SC is appropriate as it manifests in sicker hospitalized patients with numerous comorbidities. We review the limited but provocative literature pertinent to SC in the critically ill and describe important clues to identify global, subclinical and probable forms of SC. We illustrate the several unique clinical features, demographic differences and propose a diagnostic algorithm to optimize cardiac care in the critically ill.

Manifestation of Latent Left Ventricular Outflow Tract Obstruction in the Acute Phase of Takotsubo Cardiomyopathy

Objective Left ventricular outflow tract (LVOT) obstruction is a complication in 15-25% of patients with Takotsubo cardiomyopathy and sometimes leads to catastrophic outcomes, such as cardiogenic shock or cardiac rupture. However, the underlying mechanisms have not been clarified. Methods and Results We experienced 22 cases of Takotsubo cardiomyopathy during 3 years, and 4 of these 22 cases were complicated with LVOT obstruction in the acute phase (mean age 79±5 years, 1 man, 21 women). The LVOT pressure gradient in the acute phase was 100±17 mmHg. Transthoracic echocardiogram (TTE) revealed left ventricular hypertrophy (LVH) in one case and sigmoid-shaped septum without LVH in three cases. The complete resolution of the LVOT obstruction was achieved in a few days with normalization of the left ventricular wall motion following administration of beta-blockers. A dobutamine provocation test after normalization of the left ventricular wall motion reproduced the LVOT obstruction in all cases and revealed the presence of latent LVOT obstruction. Conclusion The manifestation of latent LVOT obstruction in the acute phase of Takotsubo cardiomyopathy is one potential reason for the complication of LVOT obstruction with Takotsubo cardiomyopathy.

Dynamic left ventricular outflow obstruction in situs inversus with levocardia

A 69-year-old man with situs inversus, levocardia and inverted great arteries developed severe dynamic left ventricular outflow tract (LVOT) obstruction with systolic anterior motion of the anterior mitral leaflet. There was no asymmetric septal hypertrophy. A possible mechanism of the LOVT obstruction in the present case may have been related to an abnormally long and bent outflow tract resulting from overriding of the right ventricle over the LVOT due to a congenital malposition of the heart. Mitral valve replacement with septal myectomy was performed in order to eliminate systolic anterior motion. The postoperative course has been excellent.

Dynamic obstruction induced by systolic anterior motion of the mitral valve in a volume-depleted left ventricle: an unexpected cause of acute heart failure in a patient with chronic obstructive pulmonary disease

Systolic anterior motion (SAM) of the mitral valve (MV) and left ventricular outflow tract (LVOT) dynamic obstruction (DO) typically occur in hypertrophic cardiomyopathy; however, they can appear in an apparently normal heart in association with changes in cardiac loading conditions and/or hyperdynamic left ventricular (LV) performance. Meanwhile, chronic obstructive pulmonary disease (COPD) can impair LV filling by elevating pulmonary vascular resistance. The authors report a case of transient acute heart failure caused by LVOT DO resulting from SAM of the MV in a severely volume-depleted LV in a patient with acute COPD exacerbation.

An autopsy report of acute myocardial infarction with hypertrophic obstructive cardiomyopathy-like heart

An 84-year-old woman, who was followed up as hypertrophic obstructive cardiomyopathy (HOCM) in a local hospital, was transferred to our center because of anterior chest pain and diagnosed with acute myocardial infarction (MI). Coronary angiography showed total occlusion of the mid-left anterior descending, and flow was restored after endovascular thrombectomy. An autopsy was performed after she died on hospital day 6. At autopsy, there was no significant stenosis in this vessel and the absence of plaque rupture was confirmed. Likewise, it was unclear asymmetric hypertrophy at autopsy, it could not deny that a sigmoid deformity of the basal septum occurs in elderly patients and can mimic the asymmetric septal hypertrophy of hypertrophic cardiomyopathy. MI was thought to be caused by coronary spasm or squeezing in HOCM-like heart. Therefore, it may be necessary antithrombosis therapy in HOCM-like patients with no history of paroxysmal atrial fibrillation.

Early dynamic left intraventricular obstruction is associated with hypovolemia and high mortality in septic shock patients

Introduction

Based on previously published case reports demonstrating dynamic left intraventricular obstruction (IVO) triggered by hypovolemia or catecholamines, this study aimed to establish: (1) IVO occurrence in septic shock patients; (2) correlation between the intraventricular gradient and volume status and fluid responsiveness; and (3) mortality rate.

Method

We prospectively analyzed patients with septic shock admitted to a general ICU over a 28-month period who presented Doppler signs of IVO. Clinical characteristics and hemodynamic parameters as well as echocardiographic data regarding left ventricular function, size, and calculated mass, and left ventricular outflow Doppler pattern and velocity before and after fluid infusions were recorded.

Results

During the study period, 218 patients with septic shock were admitted to our ICU. IVO was observed in 47 (22 %) patients. Mortality rate at 28 days was found to be higher in patients with than in patients without IVO (55 % versus 33 %, p < 0.01). Small, hypercontractile left ventricles (end-diastolic left ventricular surface 4.7 ± 2.1 cm²/m² and ejection fraction 82 ± 12 %), and frequent pseudohypertrophy were found in these patients. A rise ≥12 % in stroke index was found in 87 % of patients with IVO, with a drop of 47 % in IVO after fluid infusion.

Conclusion

Left IVO is a frequent event in septic shock patients with an important correlation with fluid responsiveness. The mortality rate was found to be higher in these patients in comparison with patients without obstruction.

Manifestation of latent left ventricular outflow tract obstruction caused by acute myocardial infarction: An important complication of acute myocardial infarction

BACKGROUND

Although transient left ventricular outflow tract (LVOT) obstruction is reported as a complication with acute myocardial infarction (AMI), the mechanisms and features of LVOT obstruction in AMI are unclear.

METHODS AND RESULTS

Herein, we present two cases of transient LVOT obstruction with anteroseptal AMI. The features of these two cases were one-vessel disease (1-VD) of the left anterior descending artery (LAD) and maintenance of blood flow to the major septal branch (SB). Moreover, LVOT obstruction was revealed after dobutamine infusion in the chronic phase and the aorto-septal angle was low in these two cases, meaning that latent LVOT obstruction was due to sigmoid-shaped septum.

CONCLUSIONS

Latent LVOT obstruction would be manifested in the acute phase of AMI. 1-VD of LAD and the maintenance of major SB blood flow are important factors with respect to the manifestation of latent LVOT obstruction.

CRITICAL CARE ECHO ROUNDS: Haemodynamic instability

The use of echocardiography, whilst well established in cardiology, is a relatively new concept in critical care medicine. However, in recent years echocardiography's potential as both a diagnostic tool and a form of advanced monitoring in the critically ill patient has been increasingly recognised. In this series of Critical Care Echo Rounds, we explore the role of echocardiography in critical illness, beginning here with haemodynamic instability. We discuss the pathophysiology of the shock state, the techniques available to manage haemodynamic compromise, and the unique role which echocardiography plays in this complex process.

Left ventricular outflow tract obstruction following an uncomplicated primary percutaneous coronary intervention: a recognized but rare cause of cardiogenic shock

Dynamic left ventricular outflow tract obstruction is a rare but important complication of myocardial infarction. It occurs acutely and may mimic the presentation of papillary muscle rupture or acquired ventricular septal defect. Unlike these mechanical complications, it does not require circulatory support or cardiac surgical intervention. Recognition is critical because it typically responds to volume loading and beta blockade. We report a case who displayed many classical features of this condition.

Left ventricular outflow tract obstruction with systolic anterior motion of the mitral valve in patient with pericardial effusion caused by ascending aortic dissection -A case report-

Left ventricular outflow tract (LVOT) obstruction with systolic anterior motion (SAM) of mitral valve is not only limited to patients with hypertrophic cardiomyopathy. A diagnosis of LVOT obstruction with SAM is important because conventional inotropic support may potentially aggravate hemodynamic deterioration. We present a case of LVOT obstruction with SAM in a patient who underwent an emergent surgery for ascending aortic dissection with pericardial effusion. The patient showed refractory hypotension after standard pharmacologic interventions during induction of anesthesia. Transesophageal echocardiography (TEE) revealed LVOT obstruction with SAM and it was managed appropriately under the guidance of TEE. Intraoperative TEE can play an important role in diagnosis and management of LVOT obstruction with SAM caused by pericardial effusion.

Intra-aortic balloon pump induced dynamic left ventricular outflow tract obstruction and cardiogenic shock after very late stent thrombosis in the left anterior descending coronary artery

An 81-year-old woman had undergone percutaneus coronary intervention to mid left anterior descending coronary artery with a drug-eluting stent for effort angina pectoris. Although she had remained asymptomatic for 3 years, she developed cardiogenic shock following acute myocardial infarction due to stent thrombosis. Her condition deteriorated despite successful revascularization and an initiation of intra-aortic balloon pump (IABP). Transthoracic echocardiography examination revealed systolic anterior motion of the anterior mitral leaflet which caused severe left ventricular outflow tract obstruction (LVOTO) and moderate mitral regurgitation. Discontinuation of IABP resulted in immediate and complete recovery from cardiogenic shock and echocardiography revealed no LVOTO. These findings may shed new light on the underlying mechanism responsible for deteriorating LVOTO and yield new insights into the assessment and the treatment of cardiogenic shock with dynamic LVOTO.

Isolated dynamic left ventricular outflow tract obstruction can cause hypotension that rapidly responds to intravenous beta blockade

Dynamic left ventricular outflow tract obstruction occurs in hypertrophic cardiomyopathy, stress cardiomyopathy, acute coronary syndromes, and with inotrope use. We describe three critical care patients who developed "isolated" left ventricular outflow tract obstruction with hypotension in the absence of these precipitants. Systolic anterior motion of anterior mitral valve leaflet with peak left ventricular outflow tract gradients of greater than 120 mmHg was noted in Cases 1 and 2. Under close supervision, intravenous (IV) β blocker was initiated with 5 mg metoprolol repeated every 5 minutes up to 15 mg and continued to maintain heart rate less than 70 beats/min. IV fluids were replaced aggressively. Bedside Doppler echocardiogram confirmed near normalization of left ventricular outflow tract gradient with improvement in systolic anterior motion and hypotension within minutes after IV β blocker confirming its specific therapeutic effect. Isolated left ventricular outflow tract obstruction can occur in the absence of recognized precipitants. Early recognition is crucial because this potentially fatal condition responds well to adequate β blocker and IV fluids with rapid relief of hypotension and symptoms.

Anterior myocardial infarction with dynamic left ventricular outflow tract obstruction

We present the case of a 78-year-old woman who presented with acute anterior myocardial infraction. An intraoperative transesophageal echocardiogram revealed an akinetic apex with hyperkinesis of the basal segments causing systolic anterior motion of the mitral valve. The patient was immediately placed on cardiopulmonary bypass. Her postoperative course was uneventful. We present transesophageal and transthoracic echocardiographic videos showing this unique complication and describing the challenge of managing a patient who required opposing therapies.

Pathophysiology of dynamic left ventricular outflow tract obstruction in a critically ill patient

Left ventricular outflow tract obstruction is not a rare problem in the intensive care units and can precipitate hemodynamic shock unresponsive to catecholamine therapy. The use of echocardiographic examination is extremely important in recognizing this phenomenon and its underlying conditions, finally identifying the most appropriate therapeutic strategy. The simple correction of one or more of these factors can dramatically change patients clinical outcome. We report the clinical case of a 72-year-old man who developed hemodynamic shock in the intensive care unit. Hypovolemia, catecholamine infusion, and mechanical ventilation induced geometric modification of the left ventricle causing a systolic anterior motion of the mitral anterior leaflet and a severe subaortic gradient. Simple restoration of fluids and discontinuation of medical therapy dramatically changed the outcome of the patient. A review of the medical literature has been carried out to deeply investigate pathophysiology of left ventricular outflow tract obstruction in critically ill patients.

[Ventricular dysfunction and acute pulmonary edema related to intraoperative hypertensive crisis: a case report of clinical and echocardiographic assessment]

A 39-year-old obese woman underwent surgery to open an obstructed tear duct under general anesthesia. After reversal of the neuromuscular block, the patient had a sudden, severe increase in blood pressure related to nonsustained monomorphic ventricular tachycardia. Acute pulmonary edema and cardiogenic shock developed minutes after treatment with propranolol, labetalol, and nitroglycerin. Intraoperative transesophageal echocardiography showed severe diffuse left ventricular hypokinesis with an ejection fraction under 15%. Hemodynamic stability was achieved with inotropic infusions. Angiography ruled out coronary artery injury and echocardiographic follow-up revealed progressive improvement of ventricular function. We analyze diagnostic possibilities and describe the benefits of echocardiography in the diagnosis and treatment of intraoperative acute heart failure.

Therapeutic challenges in combined apical ballooning syndrome and acute pulmonary decompensation

Apical ballooning syndrome (ABS) is increasingly diagnosed in critical care settings. Widespread application of echocardiography and cardiac enzyme testing has increased its recognition. Our experience of 4 subjects illustrates the association of ABS with a wide spectrum of acute pulmonary disorders seen in critical care settings. All had ABS proven by normal coronary angiogram and subsequent normalization of left ventricular dysfunction. Bronchospasm due to chronic obstructive pulmonary disease exacerbation or cardiac failure warrants the use of beta agonists. ABS, on the other hand, being caused by excess sympathetic activity could potentially improve with beta blockade. Coexistence of ABS and pulmonary disease in critical-care settings presents unique therapeutic challenges and outcomes can be optimized by judicious use of available medical options.

Acute left ventricular dysfunction in the critically ill

Acute left ventricular (LV) dysfunction is common in the critical care setting and more frequently affects the elderly and patients with comorbidities. Because of increased mortality and the potential for significant improvement with early revascularization, the practitioner must first consider acute coronary syndrome. However, variants of stress (takotsubo) cardiomyopathy may be more prevalent in ICU settings than previously recognized. Early diagnosis is important to direct treatment of complications of stress cardiomyopathy, such as dynamic LV outflow tract obstruction, heart failure, and arrhythmias. Global LV dysfunction occurs in the critically ill because of the cardio-depressant effect of inflammatory mediators and endotoxins in septic shock as well as direct catecholamine toxicity. Tachycardia, hypertension, and severe metabolic abnormalities can independently cause global LV dysfunction, which typically improves with addressing the precipitating factor. Routine troponin testing may help early detection of cardiac injury and biomarkers could have prognostic value independent of prior cardiac disease. Echocardiography is ideally suited to quantify LV dysfunction and determine its most likely cause. LV dysfunction suggests a worse prognosis, but with appropriate therapy outcomes can be optimized.

Mechanical versus pharmacologic support for cardiogenic shock

Dynamic left ventricular outflow tract obstruction is a rare cause of cardiogenic shock after an acute myocardial infarction. A case is presented where inotropic support and an intra-aortic balloon pump aggravated the cardiac hemodynamics by this mechanism. The circulatory support provided by Impella 2.5 heart pump, in addition to discontinuation of inotropic support and intra-aortic balloon pump, allowed stabilization and successful percutaneous revascularization.

Echocardiography in stress cardiomyopathy and acute LVOT obstruction

Widespread use of echocardiography has contributed to more frequent recognition of takotsubo stress cardiomyopathy. Initial presentation is similar to acute coronary syndrome and the acute course can be complicated by heart failure, arrhythmias, dynamic left ventricular outflow tract obstruction, hypotension and death. We briefly review the clinical presentation and propose a unified diagnostic algorithm for cardiologists acutely managing this cardiac emergency. We highlight the central role of echocardiography and emphasize the nuances of this peculiar acute cardiomyopathy from an echocardiographers' perspective.

Haemodynamic effects of acute intravenous metoprolol in apical ballooning syndrome with dynamic left ventricular outflow tract obstruction

Takotsubo syndrome, also called apical ballooning syndrome, is a clinical entity characterized by transient hypokinesis, akinesis, or dyskinesis of the left ventricular mid-segments with or without apical involvement, and without obstructive coronary lesions. The contemporary presence of left ventricular outflow tract obstruction (LVOTO), systolic anterior motion of the anterior mitral leaflet, and acute mitral regurgitation might explain the worsening of the heart failure or the occurrence of cardiogenic shock in some patients with apical ballooning syndrome. The use of beta-blockers should improve the LVOTO gradient by reducing basal hypercontractility, increasing left ventricular filling and size, and reducing heart rate. However, clear evidence of the direct haemodynamic effects of beta-blockers is still lacking. We present a case of apical ballooning syndrome complicated by dynamic LVOTO, treated with metoprolol.

Unexplained hypotension: the spectrum of dynamic left ventricular outflow tract obstruction in critical care settings

OBJECTIVE

To illustrate the clinical and hemodynamic abnormalities caused by dynamic left ventricular outflow tract obstruction (LVOTO) in critical care setting.

DESIGN

We reviewed cases referred to Cardiology with echocardiographic evidence of LVOTO and their clinical presentations. We present those cases where LVOTO can transiently occur without hypertrophic cardiomyopathy when inotropic agents are used for hypotension.

MEASUREMENTS AND MAIN RESULTS

Five women in the 50-70 age range and prior history of hypertension presented with various symptoms like chest discomfort, fatigue, dizziness, atrial fibrillation, and hypotension. An ejection systolic murmur was noted most often in the left third intercostal space and ECG revealed ST-T wave abnormalities. LVOTO caused by mitral systolic anterior motion was detected by echocardiography and catheterization excluded acute coronary disease. In critical care setting, LVOTO can occur due to apical ballooning syndrome, coronary disease, medications, volume depletion, and valvular abnormalities. Because this condition mimics acute coronary syndrome or other etiologies of hypotension in medical and surgical intensive care units, appropriate treatment can be delayed. Nonhypertrophic cardiomyopathy LVOTO usually responds well to fluid replacement, beta blockers, and medication changes.

CONCLUSIONS

LVOTO should be suspected especially in women presenting with hypotension and systolic murmur in critical care settings. Clinical acumen and timely echocardiography are required to effectively counter this transient but potentially lethal problem.

Usefulness of two-dimensional speckle tracking echocardiography for assessment of Tako-Tsubo cardiomyopathy

The aim of this study was to characterize left ventricular (LV) systolic function using 2-dimensional strain in Tako-Tsubo cardiomyopathy (TTC). Forty-two women were prospectively studied using 2-dimensional speckle-tracking echocardiography, divided into 3 groups: 14 patients with TTC (group 1), 14 patients with coronary artery disease (group 2), and 14 healthy patients (group 3). In patients with TTC, mean values of systolic peak velocity, strain, and strain rate were significantly lower than those in group 3 (p <0.04), but these values were similar between the basal septum and lateral wall, between the middle septum and lateral wall, and between the apical septum and lateral wall. LV ejection fractions were significantly improved during follow-up (p <0.0001). All values of velocities were significantly increased at day 7 compared with the acute phase (p < or =0.01). This improvement differed between the middle septum and lateral wall (p <0.0001), and values for the middle septum and lateral wall in patients with TTC were not significantly different from those observed in patients with coronary artery disease (p = NS). At 1-month follow-up, no significant difference was noted between patients in groups 1 and 3. In conclusion, 2-dimensional speckle-tracking echocardiography is a reliable tool for assessing circular dysfunction in patients with TTC. Once the acute phase has passed, TTC may mimic the LV systematized dysfunction observed in patients with coronary artery disease and so lead to misdiagnosis. This novel echocardiographic technique can also be used in the follow-up of LV functional recovery.

Prevalence and characteristics of left ventricular outflow tract obstruction in Tako-Tsubo syndrome

BACKGROUND AND OBJECTIVE

Tako-Tsubo syndrome is a clinical entity mimicking acute coronary syndrome (ACS). Left ventricular outflow tract (LVOT) obstruction may occur in Tako-Tsubo syndrome. The aim of this study was to determine the prevalence and features of LVOT obstruction in Tako-Tsubo syndrome in a population presenting with ACS.

METHODS

This study included consecutive patients admitted to 2 catheterization laboratories for suspected ACS. All patients underwent echocardiography, coronary arteriography, and left ventricular angiography if no significant coronary lesions were found.

RESULTS

Among 10,366 patients referred for coronary angiography, the study population consisted of 3,909 patients with suspected ACS. Thirty-two patients (mean age 71 +/- 13 years old) presented with Tako-Tsubo syndrome, resulting in a prevalence of 0.8% in our population of ACS and 5% of patients without significant coronary lesions. Eight women (mean age 81 +/- 4 years old, P = .01) exhibited LVOT obstruction, a prevalence of 25% among Tako-Tsubo syndrome cases. All patients with intraventricular pressure gradient had systolic anterior motion of the mitral valve and septal bulge. Prevalence of septal bulge was 100% in patients with Tako-Tsubo syndrome and LVOT obstruction versus 29% in patients without LVOT obstruction (P = .002). Mean degree of mitral regurgitation was 2.1 +/- 0.7 in cases of LVOT obstruction versus 0.9 +/- 0.7 in patients without LVOT (P = .0003) and significantly decreased during follow-up (1 +/- 0.8, P = .002). Recovery of left ventricular ejection fraction was similar in patients with and without LVOT obstruction (P = .58).

CONCLUSIONS

The present study demonstrates that the prevalence of LVOT obstruction in Tako-Tsubo syndrome is high, with specific characteristics as compared with patients without LVOT obstruction. Echocardiography should be systematically performed for all patients presenting with Tako-Tsubo syndrome for the detection of LVOT obstruction.