Dynamic Outflow Obstruction Research Articles

Abstract 16265: Precipitants of Acute Hemodynamic Instability in Patients With Hypertrophic Cardiomyopathy Admitted to the Cardiac Intensive Care Unit

Background: Hypertrophic cardiomyopathy (HCM) is the most common genetic heart disease in the United States which can infrequently present with acute hemodynamic instability. Our study aimed to identify the precipitants of acute cardiovascular decompensation resulting in Cardiac Intensive Care Unit (CICU) admission in patients with HCM. Methods: All patients admitted to Cleveland Clinic Cardiac Intensive Care Unit (CICU) between Jan 1 st , 2010, to Dec 31 st , 2021, with a diagnosis of CS and co-existing HCM were identified through electronic medical charts. Only those with previously uncorrected HCM in the form of no prior myectomy/alcohol septal ablation and not on mavacamten were included in our study. Chart review was performed by physician investigators to identify the etiology precipitating hemodynamic instability in these patients. Results: Overall, 2754 patients were admitted to our CICU with CS during the study period, of which 21 patients (1%) had coexisting uncorrected HCM. The median age of patients with HCM admitted to our CICU was 61 years, 52% (n=11) were females, and 86% (n=18) were White Americans. The in-hospital mortality of patients with HCM-CS was around 24% (n=5). Retrospective chart review to identify the precipitating agent revealed atrial fibrillation with rapid ventricular response (Afib-RVR) to be the most common precipitant (33%, n=7), followed by severe MR in the setting of dynamic outflow obstruction (19%, n=4) and non-obstructive heart failure (19%, n=4). Conclusion: Identification of the precipitating mechanisms is critical to manage HCM patients presenting with hemodynamic instability. Rapid atrial fibrillation appears to be the most common precipitant leading to hemodynamic instability in this population.

786 SYSTOLIC ANTERIOR MOVEMENT OF MITRAL VALVE: NOT ONLY HYPERTROPHIC CARDIOMYOPATHY, BUT ALSO CARDIAC AMYLOIDOSIS

Abstract A 71 years-old man was diagnosed with lambda light chain multiple myeloma evolving from monoclonal gammopathy of unknown significance during hematological follow-up. Serum creatinine and blood urea were normal, but proteinuria was significant. A subsequent renal biopsy showed amyloid deposits in renal glomeruli. He had no comorbidities or previous cardiologic history. To provide a complete diagnostic work-up, an echocardiogram was performed, showing marked and asymmetric left ventricular hypertrophy (interventricular septum diastolic thickness IVSd 15 mm) with dynamic left ventricular outflow tract obstruction (LVOTO) due to an incomplete systolic anterior motion (SAM) of mitral valve. ECG showed sinus rhythm with 1st degree atrio-ventricular block; notably, there was no electrocardiographic sign of left ventricular hypertrophy. Therefore, a Cardiac Magnetic Resonance (CMR) was performed, showing left ventricular hypertrophy (interventricular septum thickness 15 mm) with normal contractility. Mild left atrial enlargement and thickening of the interatrial septum were found, together with mild circumferential pericardial effusion. No perfusion defects were recorded, but late gadolinium enhancement (LGE) pattern was not assessable because of difficult myocardial signal nulling point. These findings were consistent with cardiac amyloidosis (CA). By the time, histological demonstration of amyloid was mandatory, so an endomyocardial biopsy was performed. Amyloid deposits were found to be in the myocardial interstitial space and into the myocardial vessel walls. Immunohistochemical staining revealed diffuse and high reactivity for lambda free light chains and moderate reactivity for kappa chains. No transthyretin was found in the specimens. Finally, a diagnosis of AL amyloidosis with cardiac and renal involvement associated with lambda light chain multiple myeloma was made and chemotherapy with bortezomib, thalidomide and dexamethasone (VTD) was started. During the cardiologic follow-up, three syncope with prodromal symptoms have occurred. In all these circumstances, no arrhythmias were found at prolonged ECG Holter monitoring. Echocardiogram showed a progression of the dynamic outflow obstruction to 80 mmHg and increasing mitral regurgitation associated with complete systolic anterior motion of the valve. Given the echocardiographic features and the clinical events, we performed a genetic blood test which excluded sarcomeric genes mutations. Also, familial screening with ECG and echocardiogram was negative. A better management of pharmacological therapy, together with avoidance of hypovolemia and supportive treatment of anemia finally relieved patient's symptoms. Conclusions we presented this case to underline that, although rare, cardiac amyloidosis can resemble other hypertrophic cardiomyopathies with left ventricular outflow tract obstruction due to SAM of the mitral valve and irregular septal hypertrophy, caused by amyloid deposits. Most of these cases are seen in the senile transthyretin type, but sometimes they are observed in AL patients. Nowadays, it is crucial to diagnose these patients correctly as early treatment is critical for survival in this population.

Transcatheter Mitral Intervention Relieves Dynamic Outflow Obstruction and Reduces Cardiac Workload in Hypertrophic Cardiomyopathy.

Transcatheter Mitral Intervention Relieves Dynamic Outflow Obstruction and Reduces Cardiac Workload in Hypertrophic Cardiomyopathy.

A novel technique for invasive aortic valve pressure gradient measurement using a 6 Fr Swan-Ganz catheter: a case series

BackgroundSimultaneous left ventricular (LV) and aortic (Ao) pressure gradient assessment has been rendered challenging since the recall of the Langston catheter. Here we describe a simple method for simultaneous LV and Ao pressure gradient assessment using a Swan-Ganz catheter.Case summaryWe describe two cases where assessment of simultaneous left ventricle and Ao valve gradients was done using a Swan-Ganz catheter to assess the degree of Ao stenosis and dynamic LV outflow obstruction.DiscussionUsing Swan-Ganz catheter assessment of simultaneous left ventricle and Ao valve gradients can simplify the procedure with reduced cost and increased patient safety.

Distinctive Hypertrophic Cardiomyopathy Anatomy and Obstructive Physiology in Patients Admitted With Takotsubo Syndrome

Clinical spectrum of hypertrophic cardiomyopathy (HC) has been expanded to include patients with mild or no thickening of the left ventricle (LV), who nevertheless have outflow tract obstruction at rest or after exercise, due to systolic anterior motion (SAM) and ventricular septal contact, with mitral valve elongation and papillary muscles anomalies. Apical ballooning mimicking a takotsubo syndrome (TS) wall motion pattern can occur in HC with mild septal thickening when latent obstruction becomes unrelenting. To define the prevalence of anatomic abnormalities characteristic of HC in patients diagnosed with TS, we analyzed echocardiograms of 44 unselected TS patients, age 67±12 years, 95% women including studies performed before the event (n = 11, median 515 days) and after recovery of left ventricular function (n = 33, median 92 days, interquartile range = 29 to 327) and compared the findings to 60 age and sexed matched controls. Analysis of echocardiograms was blinded to event timing, and patient vs. control status. During the ballooning event, 13 patients (30%) had SAM including 9 with LV outflow obstruction, peak gradients 71±40 mmHg, as well as: ventricular septal thickening (16 ± 4 mm), elongated anterior leaflets (30 ± 3mm), and increased mitral coaptation to posterior wall distance (17 ± 5 mm), consistent with diagnosis of the HC phenotype. Compared to 31 TS patients without SAM, study patients with SAM had longer anterior leaflets (30 ± 3 vs 26 ± 4 mm, p = 0.006), thicker septum (16 ± 4 vs 12 ± 3 mm), increased coaptation to posterior wall distance (17 ± 5 vs 14 ± 4 mm, p < 0.04) and reduced distance from coaptation to septum (19 ± 5 vs 27 ± 5, p < 0.001). In the 13 patients with SAM, morphologic characteristics of HC persisted after normalization of LV function. In conclusion, a subset of patients experiencing TS events demonstrates a constellation of morphologic abnormalities characteristic of HC that persist after recovery of LV wall motion. These findings suggest that dynamic outflow obstruction may cause apical ballooning in susceptible patients.

Cardiac Arrest Due to Severe Dynamic Left Ventricular Outflow Obstruction and Hypertrophy Following Anesthesia Induction

Cardiac arrest following induction of general anesthesia is a rare event. A 47-year-old woman with a history of chronic neck pain secondary to spinal stenosis presented for elective cervical laminectomy. Induction of general anesthesia induced cardiac arrest and emergency insertion of the transesophageal echocardiogram probe identified severe, undiagnosed left ventricular hypertrophy with dynamic outflow obstruction. Resuscitative treatment was immediately implemented to include aggressive intravenous fluid resuscitation, intravenous esmolol and phenylephrine to augment preload, afterload, and reflex bradycardia effect. Return of spontaneous circulation was achieved and the patient was admitted to the ICU, where she was extubated with preserved neurocognitive function on the same day. Our case describes the risk presented by undiagnosed cardiac abnormalities in what was accepted as a low-to-intermediate risk patient undergoing an elective procedure. The increasing popularity and use of pocket-sized handheld ultrasound devices may help reduce the risk of occurrences such as this in the future.

Takotsubo cardiomyopathy: A discussion and case study

Takotsubo cardiomyopathy (TCM), first reported by Japanese doctors, has gained an overall acknowledgment as an independent malady of international attention. It resembles the presentation of an acute myocardial infarction but lacks ischemic myocardial tissue. The objective of this article is to review the physiology, diagnostics, treatment, and complications of TCM and report a case study of a patient who developed TCM. Observation through direct patient care allowed for data collection of this unique medical phenomenon. Supporting information was obtained via investigation of scholarly articles on TCM over the past 10 years. Although TCM is usually transient, it is important to quickly differentiate TCM from other more serious medical conditions, such as myocardial infarction, pulmonary embolism, and pheochromocytoma. Typical diagnostic workup includes electrocardiography, cardiac biomarkers, and echocardiography or coronary angiography. Complications include cardiogenic shock, left ventricular wall rupture, and life-threatening arrhythmias. The advanced practice nurse (APN) is instrumental in differentiating between TCM versus acute myocardial infarction, heart failure, pulmonary edema, dynamic outflow obstruction, and cardiogenic shock. Because of these possible acute and critical presentations, prompt recognition and intervention for patients with TCM are priorities for nurse practitioners.

A clinically and echocardiographically demonstrable dynamic left ventricular outflow tract obstruction

Dynamic left ventricular outflow tract (LVOT) obstruction is a distinctive finding on echocardiography and often supports a diagnosis of hypertrophic obstructive cardiomyopathy (HOCM). It is also a clinical entity in its own right and is reproducible with stress. We describe a case of dynamic outflow obstruction in an elderly man with classical exertional symptoms. Echocardiography was used to demonstrate a variable gradient, with imaging performed at rest and following physical exertion. We will review the pathophysiological changes seen in this condition, both in terms of cardiac structure and the physics of fluid dynamics. Medical treatment is centered around a meaningful understanding of these changes, but there are also surgical and ablative options available. Device therapy with an implantable cardioverter-defibrillator (ICD) is the mainstay of HOCM treatment, particularly when ventricular arrhythmias are evident. A risk stratification for sudden cardiac death from hypertrophic cardiomyopathy is imperative in case by case management.

September 2016 at a glance: pregnancy, hypertrophic cardiomyopathy, epidemiology, medical treatment.

Peripartum cardiomyopathy is a major cause of heart failure (HF) towards the end of pregnancy and in the months after delivery. Its prevalence and clinical characteristics are collected in a large registry by the EURObservational Research Programme.1 In this issue of the journal, practical recommendations for the diagnosis and management of severe acute peripartum cardiomyopathy are given by the task force of the Heart Failure Association (HFA) of the European Society of Cardiology (ESC).2 In another article, based on the ESC Registry Of Pregnancy and Cardiac Disease, Sliwa et al. analyse the clinical characteristics and outcomes of 151 women with pulmonary hypertension during pregnancy.3 Maternal and fetal mortality remains excessively high in these subjects with a high rate of HF (27%) and of fetal complications. These were particularly high in the mothers with severe pulmonary hypertension and idiopathic pulmonary arterial hypertension.3 Current treatment of hypertrophic cardiomyopathy is reviewed by Ammirati et al.4 In addition to traditional medical therapy, specific clinical problems, such as treatment of dynamic outflow obstruction, HF caused by end-stage progression, and prevention of atrial fibrillation and ventricular arrhythmias are assessed. Future developments with new treatments, based on pre-clinical research, starting to be assessed in randomized clinical trials, are also discussed.4 Farré et al. present data on all the 88 195 cases with HF detected in Catalonia (Spain) in 2012. One-year mortality rate was 14%, and 53.4% and 30.8% of the patients needed at least one emergency department visit or an unplanned hospitalization, respectively. The costs for HF treatment encompassed 7.1% of the total healthcare budget with hospitalizations and co-morbidities as its main determinants.5 These data confirm those of previous studies,6, 7 and are collected in a large cohort of unselected patients from the single geographical area of Catalonia. Fifteen-year trends in the prevalence, management and outcomes of cardiogenic shock in France are shown by Aissaoui et al.8 Consistent with recent data from other countries,9 the Authors show a decrease in mortality, concomitant not only with the larger use of percutaneous coronary interventions but also with better global patients' assessment and follow-up.8 A consistent proportion of patients with non-valvular atrial fibrillation, and a potential indication to non-vitamin K antagonist oral anticoagulants (NOACs), have HF.10, 11 Analyses from the recent trials comparing them with warfarin are therefore important.12 In this issue of the journal, Magnani et al. examine the results of edoxaban, compared with warfarin, in the 8145 patients with HF enrolled in the ENGAGE AF-TIMI 48 trial. Similar to the overall results of the trial, edoxaban, in its higher dose regimen, was effective in preventing stroke and systemic thromoboembolic events and was associated with a lower risk of major bleeding, compared with warfarin, in the patients with HF.13 The potential impact of renal function on treatment with NOACs in patients with HF and atrial fibrillation is examined by Hawkins et al. using the data from the CHARM programme.14 Patients with atrial fibrillation had a worse renal function compared with those in sinus rhythm. Patients with atrial fibrillation had at least a moderate impairment in renal function in a quarter of the cases, at baseline, and in a third, at the end of the study, with almost half who had renal dysfunction at least once during follow-up. Hence, the projected need for NOAC dose reduction was high, though with differences between individual NOACs due to different criteria for adjustment. Need of cessation would have been, however, rare.14 An analysis from the EMPHASIS-HF (Eplerenone in Mild Patients Hospitalization and SurvIval Study in Heart Failure) trial shows the lack of impact of aspirin on the beneficial effects of eplerenone on outcomes with, therefore, different results from those described with ACE inhibitors in some studies.15 The impact of chronic exposure to ivabradine on early readmissions in patients hospitalized for HF during the course of the SHIFT study (Systolic Heart Failure treatment with the If inhibitor ivabradine Trial) is analysed by Komajda et al.16 Ongoing ivabradine treatment was associated with fewer all-cause hospitalizations at 1, 2 and 3 months, confirming its beneficial effects on rehospitalizations.16 Senni et al. have compared two uptitration protocols of sacubitril/valsartan from 50 to 200 mg twice daily (target dose), over 3 and 6 weeks, respectively, in HF patients. Rates for adverse effects (hypotension, renal dysfunction, hyperkalaemia) were similar with the two regimens. The proportion of patients who achieved and maintained the target dose of sacubitril/valsartan 200 mg twice was similar, except in the pre-specified group of patients who were initially on low ACE inhibitor/angiotensin receptor blocker doses, who reached target sacubitril/valsartan doses at higher rates with the slow uptitration regimen, compared with the faster one (85% vs. 74%, P = 0.030).17

Pharmacological treatment of hypertrophic cardiomyopathy: current practice and novel perspectives.

Hypertrophic cardiomyopathy (HCM) is entering a phase of intense translational research that holds promise for major advances in disease-specific pharmacological therapy. For over 50 years, however, HCM has largely remained an orphan disease, and patients are still treated with old drugs developed for other conditions. While judicious use of the available armamentarium may control the clinical manifestations of HCM in most patients, specific experience is required in challenging situations, including deciding when not to treat. The present review revisits the time-honoured therapies available for HCM, in a practical perspective reflecting real-world scenarios. Specific agents are presented with doses, titration strategies, pros and cons. Peculiar HCM dilemmas such as treatment of dynamic outflow obstruction, heart failure caused by end-stage progression and prevention of atrial fibrillation and ventricular arrhythmias are assessed. In the near future, the field of HCM drug therapy will rapidly expand, based on ongoing efforts. Approaches such as myocardial metabolic modulation, late sodium current inhibition and allosteric myosin inhibition have moved from pre-clinical to clinical research, and reflect a surge of scientific as well as economic interest by academia and industry alike. These exciting developments, and their implications for future research, are discussed.

Echocardiography quiz: Peculiar left ventricular outfl ow tract masses causing dynamic outfl ow obstruction

Echocardiography quiz: Peculiar left ventricular outfl ow tract masses causing dynamic outfl ow obstruction

Surgical septal myectomy versus alcohol septal ablation: assessing the status of the controversy in 2014.

In hypertrophic cardiomyopathy (HCM), left ventricular (LV) outflow tract obstruction, caused by mitral valve systolic anterior motion (SAM) with elevated intracavitary LV pressures, can produce disabling symptoms of heart failure and excess cardiovascular mortality.1–7 Outflow gradients are common in HCM, present in 70% of patients at rest or with physiological exercise4 (Figure 1). Fifty years ago, early HCM investigators recognized the importance of obliterating LV outflow obstruction (and mitral regurgitation) and restoring normal hemodynamics, initially with the septal myectomy operation advanced by Dr Andrew Morrow at the National Institutes of Health.6,7 However, HCM has not been immune to controversy, and through the years, several debates have focused on the significance of dynamic outflow obstruction and its treatment.7 The most recent of these conversations concerns the most effective strategy for reducing gradient and symptoms, triggered by the introduction of catheter-based percutaneous alcohol septal ablation (ASA) as an alternative to myectomy.8–19 Figure 1. Treatment algorithm for hypertrophic cardiomyopathy (HCM) patients with heart failure symptoms of exertional dyspnea with or without chest pain. LVOT indicates left ventricular outflow tract; and NYHA, New York Heart Association. The nonsurgical technique, introduced by Professor Ulrich Sigwart at the Royal Brompton Hospital in 1994,8 involves injection of 1 to 4 mL of 96% ethanol into the first septal perforator branch of the left anterior descending coronary artery to produce a basal septal myocardial infarction and ultimately remodeling of the LV outflow tract. ASA avoids the recovery time with loss of work, residual discomfort, and anxiety associated with surgery. It was soon enthusiastically embraced and heavily promoted by many clinicians and interventional cardiologists, initially in Europe, thereby expanding the treatment armamentarium of HCM and triggering a polarized and sometimes contentious debate within the cardiovascular community. Indeed, many related …

Bulging Subaortic Septum: An Important Risk Factor for Systolic Anterior Motion After Mitral Valve Repair

The purpose of this study is to determine etiologic factors of systolic anterior motion (SAM) of the mitral valve after repair. We describe 6 patients with mitral valve repair (MVRep) for degenerative mitral valve disease and a bulging angulated subaortic septum that seemed a risk factor for SAM. No patient had a hypertrophic cardiomyopathy diagnosis. All patients had an angulated septum (angle of long axis of left ventricle and aorta, >60°) with a discrete septal bulge (proximal septum, ≥1.5 cm with normal midseptal thickness). One patient had severe mitral regurgitation and became hypotensive intraoperatively, with a SAM. He had successful valve repair and septal myectomy. In 2 patients, the bulging septum was not appreciated preoperatively, and SAM developed postoperatively, causing symptomatic left ventricular (LV) outflow tract (LVOT) obstruction and recurrent mitral regurgitation. At reoperation, SAM and associated regurgitation were abolished with septal myectomy. In 2 patients undergoing mitral repair, bulging septum was identified preoperatively, and prophylactic septal myectomy was performed at valve repair. One patient was referred for valve replacement because of severe mitral regurgitation due to bileaflet prolapse and associated SAM. Doppler echocardiography showed minimal resting gradient. He had a prominent subaortic septum, and mitral regurgitation seemed due to organic valve disease and dynamic outflow obstruction. He received septal myectomy and mitral valve repair with resolution of SAM and mitral regurgitation. Bulging subaortic septum may be a risk factor for SAM after mitral valve repair. Treatment should include septal myectomy with valvuloplasty.

Hypertrophic cardiomyopathy in childhood and adolescence – strategies to prevent sudden death

Clinically overt hypertrophic cardiomyopathy is the most common cause of sudden unexpected death in childhood and has significantly higher sudden death mortality in the 8- to 16-year age range than in the 17- to 30-year age range. A combination of electrocardiographic risk factors (a limb-lead ECG voltage sum >10 mV) and/or a septal wall thickness >190% of upper limit of normal for age (z-score > 3.72) defines a paediatric high-risk patient with great sensitivity. Syncope, blunted blood pressure response to exercise, non-sustained ventricular tachycardia and a malignant family history are additional risk factors. Of the medical treatments used, only beta-blocker therapy with lipophilic beta-blockers (i.e. propranolol, metoprolol or bisoprolol) have been shown to significantly reduce risk of sudden death, with doses ≥ 6 mg/kg BW in propranolol equivalents giving around a tenfold reduction in risk. Disopyramide therapy is a very useful adjunct to beta-blockers to improve prognosis in those patients that have dynamic outflow obstruction in spite of large doses of beta-blocker, and its use in patients with hypertrophic cardiomyopathy is not associated with significant pro-arrhythmia mortality. Calcium-channel blockers increase the risk of heart failure-associated death in hypertrophic cardiomyopathy (HCM) patients with severe generalized hypertrophy and should be avoided in such patients. Amiodarone does not protect against sudden death, and long-term use in children usually has to be terminated because of side effects. Therapy with internal cardioverter defibrillator implantation has high paediatric morbidity, 27% incidence of inappropriate shocks, and does not absolutely protect against mortality but is indicated as secondary prevention or in very high-risk patients.

Valsalva maneuver, uncontrolled hypertension, asymmetric septal hypertrophy and dynamic outflow obstruction: a case report

A 83-year-old woman presented with a 25-year history of hypertension which was long-standing, uncontrolled, severe hypertension because of irregular oral administration of antihypertensive drug underwent an echocardiographic examination as part of an evaluation of hypertension. She described chest distress associated with activity, syncope for three times in the past one year. On physical examination, she was in no acute distress, with a regular pulse rate and blood pressure of 185/115 mmHg. On auscultation, her lung fields were clear. There was a III/VI late peaking crescendo/decrescendo systolic murmur along the left sternal border radiating to the apex, which increased with standing and Valsalva's maneuver and decreased with squatting. There was no report of provocative maneuvers performed during auscultation. There was no edema. Transthoracic echocardiography showed a hyperdynamic left ventricle with markedly increased left ventricular wall thicknesses and asymmetrical septal hypertrophy. M-mode echocardiography showed systolic anterior motion of the mitral valve apparatus and midsystolic closure of the aortic valve. A dynamic left ventricular outflow tract obstruction was present, with a resting maximal instantaneous gradient of 55 mmHg. With the Valsalva maneuver, the gradient increased to 114 mmHg. No any factors that could cause hypertension were found at kidney, adrenal gland and renal artery etc. by ultrasound and multislice compute tomography.

Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy

Since its original description in 1994, alcohol septal ablation (ASA) has emerged as a minimally invasive modality for treatment of hypertrophic obstructive cardiomyopathy compared to surgical myomectomy. This catheter-based intervention relies on the injection of absolute alcohol into the septal perforator to induce a controlled infarction of the hypertrophied septum and consequently abolish the dynamic outflow obstruction. This gradient reduction has been correlated with a significant clinical improvement in the patient’s symptomatology and with left ventricular remodeling. The procedure has been refined throughout the years, especially with the introduction of myocardial contrast echocardiography for localization of the area at risk of infarction and the reduction in the amount of alcohol used. Major complications of ASA are uncommon in large referral centers but conduction system disturbances has been the most commonly reported complications of ASA with 10% of patients necessitating permanent pacemaker implantation for complete heart block. ASA has not been compared to the gold standard surgical myomectomy in a randomized prospective study. We review the clinical aspects of this procedure and provide some historical background.

Invited commentary

Invited commentary

Increasing evidence for the safety and efficacy of alcohol septal ablation during medium- and long-term follow-up

Prof. Dr. Andre Keren ()) Center for Heart Failure and Heart Muscle Diseases Heart Institute Hadassah University Hospital Hadassah-Hebrew University Medical School Jerusalem 91120, Israel E-Mail: andrek@cc.huji.ac.il Hypertrophic cardiomyopathy (HCM), defined clinically by the presence of unexplained left ventricular hypertrophy [1], is the most common inherited cardiac disorder affecting one in 500 people [2, 3]. Approximately 25% of patients have left ventricular outflow obstruction at rest and 70% can develop outflow gradients during exercise [4]. The dynamic outflow obstruction is caused by the abnormal systolic contact between the hypertrophied basal interventricular septum and the anterior mitral leaflet

Asymptomatic Nonsustained Ventricular Tachycardia During Routine Stress Echocardiography

A n asymptomatic, 54-year-old man was referred by his primary care physician for a treadmill stress echocardiogram. He had been asymptomatic from a cardiovascular standpoint. He denied chest pain, dizziness, syncope, shortness of breath, or palpitations. He occasionally has a “pulling sensation” in his chest related to positional changes but not exertion. He had a 30-year history of type I diabetes mellitus treated with subcutaneous insulin. He was recently started on simvastatin, and his only other medication was aspirin. He has a strong family history of diabetes mellitus and coronary artery disease (CAD) but no family history of sudden cardiac death (SCD). The patient remains active, is normotensive, and is not overweight. The treadmill stress echocardiogram was ordered for routine screening of CAD. Baseline ECG showed normal sinus rhythm, Q waves in leads V1 and V2, and nonspecific T wave changes in the lateral leads. Several episodes of nonsustained ventricular tachycardia (NSVT) developed; the longest run was 25 beats (50 beats/min) during the terminal portion of the stress test. The tachycardia had a left bundlebranch block morphology with a monophasic R wave in II, III, and aVF. The R wave transition point was in lead V3 on the precordial leads. The rhythm was asymptomatic, resolved spontaneously, and did not occur at rest. Also, the patient showed good exercise tolerance (achieving a workload of 13 metabolic equivalents), experienced no symptoms, had a normal BP response, and showed no change in baseline ST segments. The resting echocardiogram showed a congenital bicuspid aortic valve, normal left ventricular function without segmental wall motion abnormalities, increased septal thickness (1.9 cm) without dynamic outflow obstruction, and a trace of mitral regurgitation. The stress echocardiogram showed no stress-inducible wall motion abnormalities and no ventricular dilatation. The physical examination revealed a resting BP of 118/60 mm Hg and a heart rate of 70 beats/min. The cardiac examination disclosed normal first and second heart sounds, a fourth heart sound, and a short I/VI systolic ejection murmur along the left sternal border. Peripheral pulses were equal and symmetrical. There were no carotid bruits. Lung fields were clear, and the abdomen was unremarkable. Pertinent laboratory values included hemoglobin AIc, 8.1%; total cholesterol, 196 mg/dL; low-density lipoprotein, 107 mg/dL; high-density lipoprotein, 38 mg/dL; triglycerides, 256 mg/dL; BUN, 22 mg/dL; creatinine, 0.9 mg/dL; and potassium, 4.7 mmol/L.

Alcohol Septal Ablation for Hypertrophic Obstructive Cardiomyopathy

HOCM is a rare disorder of myocardium that may result in asymmetrical left ventricular septal hypertrophy and dynamic outflow obstruction. This may result in hemodynamic sequel that leads to deterioration of functional class in the majority of patients. Alcohol septal ablation may provide symptomatic relief in the majority of patients who fail medical therapy or who experience significantly high outflow gradients.