Chadi Ayoub

Isolated hypertrophy of the basal ventricular septum: Characteristics of patients with and without outflow tract obstruction

BACKGROUND Isolated basal septal hypertrophy (IBSH) of the left ventricle (LV) is not a well understood phenomenon, particularly in the presence of concomitant left ventricular outflow tract obstruction (LVOTO). We evaluated the prevalence of IBSH and compared those with and without LVOTO. METHODS Retrospective observational study of 4104 consecutive patients undergoing echocardiography at a community cardiology practice and a hospital without specialized Hypertrophic Cardiomyopathy (HCM) service to determine prevalence of IBSH, defined as isolated hypertrophy (>15 mm) of the basal LV septum (BS) without hypertrophy elsewhere. Clinical, ECG and echocardiographic characteristics were compared in IBSH with and without LVOTO. RESULTS Prevalence of IBSH was 5.8% (240/4104): mean (SD) age was 76.0y (10.4) with equal gender distribution. Prevalence increased with age (p<0.001 for trend), reaching 7.8% over 70y. None had a family history of HCM, and HCM-associated ECG changes were uncommon. Mean BS thickness (SD) was 17.8mm (0.24) with a BS/posterior wall ratio (SD) of 1.76 (0.31). Resting peak LVOT gradient (>20mmHg) was present in 8/240 (3.3%), mean (SD) 69.6mmHg (59.3). Patients with LVOTO had hypercontractile LV function (fractional shortening [SD] 51.8% [9.5] vs. 40.5% [10.9], p=0.012) compared to those without LVOTO, but had similar BS thickness [SD] (17.8mm [3.0] vs. 17.8mm [2.8], p=0.996) and ECG characteristics. Greater apical and septal displacements of the mitral valve co-aptation point characterized those with IBSH and LVOTO. CONCLUSIONS IBSH is common in elderly patients referred for echocardiography. LVOTO occurs only when concomitant mitral valve co-aptation and LV hypercontractility facilitate development of a gradient, rather than through differences in the degree of BS myocardial hypertrophy.

A case report of ventricular dysfunction post pericardiocentesis: stress cardiomyopathy or pericardial decompression syndrome?

We report a case of transient biventricular dysfunction post therapeutic pericardiocentesis, with classic features of stress cardiomyopathy (SCM). In our patient, the clinical and echocardiographic features were more in keeping with Takotsubo-type SCM than pericardial decompression syndrome (PDS). Our case is instructive in challenging our understanding of the aetiology of LV dysfunction complicating pericardiocentesis, and in highlighting the importance of careful clinical evaluation (altered heart rate and dyspnoea) in suspecting acute LV dysfunction after initial clinical improvement with pericardial aspiration.

Cardiac Metabolism Imaging and Chemotherapy Cardiotoxicity

Cardiac oncology is a field that will become increasingly important in clinical practice as we become more effective in treating cancer and those treated with chemotherapy live longer. Potential cardiac toxicity associated with some chemotherapy treatments can cause significant morbidity. Molecular positron emission tomography (PET) to assess cardiac metabolism is a promising technology that could increase our knowledge of chemotherapy-related toxicity in the heart. We review the utility of PET cardiac imaging to evaluate the toxic effects of chemotherapy on metabolism. Free fatty acids, glucose and ketone bodies are major substrates for cardiac energy consumption, and adaptations to their use can occur under differing conditions. Cardiovascular complications of chemotherapy can include direct effects on metabolism as well as injury to myocardial tissue by effects on endothelial function, hypertension or ischemia. Even novel chemotherapies that are designed to be more specific in their actions continue to be associated with cardiotoxicity. Further study is required to understand the effects of cardiotoxicity related to chemotherapy, and to develop techniques for its detection as well as prevention. PET cardiac imaging could be used to assist in the early detection of cardiotoxicity and help guide management clinically. It may offer insights to assist in the development of novel treatments and methods for cardioprotection.

Association Between Echocardiography Laboratory Accreditation and the Quality of Imaging and Reporting for Valvular Heart DiseaseCLINICAL PERSPECTIVE

Background— It is presumed that echocardiographic laboratory accreditation leads to improved quality, but there are few data. We sought to compare the quality of echocardiographic examinations performed at accredited versus nonaccredited laboratories for the evaluation of valvular heart disease. Methods and Results— We enrolled 335 consecutive valvular heart disease subjects who underwent echocardiography at our institution and an external accredited or nonaccredited institution within 6 months. Completeness and quality of echocardiographic reports and images were assessed by investigators blinded to the external laboratory accreditation status and echocardiographic results. Compared with nonaccredited laboratories, accredited sites more frequently reported patient sex (94% versus 78%; P<0.001), height and weight (96% versus 63%; P<0.001), blood pressure (86% versus 39%; P<0.001), left ventricular size (96% versus 83%; P<0.001), right ventricular size (94% versus 80%; P=0.001), and right ventricular function (87% versus 73%; P=0.006). Accredited laboratories had higher rates of complete and diagnostic color (58% versus 35%; P=0.002) and spectral Doppler imaging (45% versus 21%; P<0.0001). Concordance between external and internal grading of external studies was improved when diagnostic quantification was performed (85% versus 69%; P=0.003), and in patients with mitral regurgitation, reproducibility was improved with higher quality color Doppler imaging. Conclusions— Accredited echocardiographic laboratories had more complete reporting and better image quality, while echocardiographic quantification and color Doppler image quality were associated with improved concordance in grading valvular heart disease. Future quality improvement initiatives should highlight the importance of high-quality color Doppler imaging and echocardiographic quantification to improve the accuracy, reproducibility, and quality of echocardiographic studies for valvular heart disease.

Comparison of Valsalva Maneuver, Amyl Nitrite, and Exercise Echocardiography to Demonstrate Latent Left Ventricular Outflow Obstruction in Hypertrophic Cardiomyopathy

Guidelines recommend exercise stress echocardiogram (ESE) for patients with hypertrophic cardiomyopathy (HC) if a 50 mm Hg gradient is not present at rest or provoked with Valsalva or amyl nitrite, to direct medical and surgical management. However, no study has directly compared all 3 methods. We sought to evaluate efficacy and degree of provocation of left ventricular outflow gradients by ESE, and compare with Valsalva and amyl nitrite. In patients with HC between 2002 and 2015, resting echocardiograms and ESEs within 1 year were retrospectively reviewed. Gradients elicited by each provocation method were compared. Rest and ESE were available in 97 patients (mean age 54 ± 18 years, 57% male); 78 underwent Valsalva maneuver and 41 amyl nitrite provocation. Median gradients (interquartile range) were 10 mm Hg (7,19) at rest, 16 mm Hg (9,34) with Valsalva, 23 mm Hg (13,49) with amyl nitrite, and 26 mm Hg (13,58) with ESE. ESE and amyl nitrite were able to provoke obstruction (≥30 mm Hg) and severe obstruction (≥50 mm Hg) more frequently than Valsalva. In patients with resting gradient <30 mm Hg (n = 83), provocation maneuvers demonstrated dynamic obstruction in 51%; in those with Valsalva gradient <30 mm Hg (n = 57), ESE or amyl nitrite provoked a gradient in 44%; and in those with amyl nitrite gradient <30 mm Hg (n = 20), ESE provoked a gradient in 29%. No demographic or baseline echocardiographic parameter predicted provocable obstruction. In conclusion, ESE is clinically useful; however, different provocation maneuvers may be effective in different patients with HC, and all maneuvers may be required to provoke dynamic obstruction in symptomatic patients.

Fixed left ventricular outflow tract obstruction mimicking hypertrophic obstructive cardiomyopathy: pitfalls in diagnosis

We present a case series that highlights the diagnostic challenges with left ventricular hypertrophy (LVH) and left ventricular outflow tract obstruction (LVOTO). Fixed structural lesions causing LVOTO with secondary LVH may mimic hypertrophic obstructive cardiomyopathy (HOCM). Management of these two entities is critically different. Misdiagnosis and failure to recognize fixed left ventricular outflow tract (LVOT) lesions may result in morbidity as a result of inappropriate therapy and delay of definitive surgical treatment. It is thus necessary to identify the correct type and level of obstruction in the LVOT by careful correlation of clinical examination, Doppler evaluation, and advanced imaging findings.

The Prognostic Value of Percentage Total Plaque Score Adjusted to Age: A Potential Marker of Coronary Vascular Age

Background: Total plaque score (TPS) on coronary computed tomography angiography (CCTA) has been validated as a surrogate measure of coronary artery disease (CAD) burden and is prognostic. We propose a novel measure, percentage TPS adjusted to age (%TPS/age), that may reflect vascular age and potentially more rapidly progressive atherosclerosis and evaluate its potential prognostic value. Methods: %TPS/age was calculated for consecutive patients prospectively enrolled into our institutional CCTA registry and evaluated for primary composite outcome of cardiac death, nonfatal myocardial infarction, and late revascularization. Results: Of 1896 patients identified (mean age 57.7 ± 11.4 years, 50.1% male, median follow-up 18.6 months [interquartile range: 15.3, 32.4]), 552 (29%) had %TPS/age = 0 (no atherosclerosis), with 1 (0.2%) primary outcome observed (annual event rate [AER] = 0.1%). Two events (0.4%, AER = 0.3%) were observed in %TPS/age < 0.314 category, 22 (5.0%, AER = 2.2%) in %TPS/age 0.314 to 0.699 category, and 54 (12.0%, AER = 5.7%) in %TPS/age ≥ 0.700 category. After adjusting for clinical predictors and obstructive CAD, higher %TPS/age category was associated with hazard ratio 1.95 (1.31-2.88, P < .001) for primary outcome on multivariable analysis, Harrell-C-Statistic 0.87 (confidence interval 95%: 0.84-0.90), and net reclassification improvement of 0.71 (P < .001). Conclusion: %TPS/Age has incremental prognostic value to traditional risk factors and CCTA measures of CAD and improves evaluation of burden of coronary atherosclerosis and clinical risk.

Successful negative inotropic treatment of acute left ventricular outflow tract obstruction by elongated mitral valve leaflet.

Elongated anterior mitral valve leaflet (EAMVL) has not been reported to cause left ventricular outflow tract obstruction (LVOTO) in the absence of left ventricular hypertrophy. We report the case of an elderly male patient who presented with acute heart failure and severe mitral regurgitation in the setting of dehydration. Echocardiography revealed acute LVOTO secondary to EAMVL. The patient was ineligible for surgery and was treated with negative inotropic agents, which ensured resolution of heart failure and marked improvement in the degree of LVOTO. This case demonstrates that, under certain circumstances, EAMVL without associated left ventricular hypertrophy may produce hemodynamic compromise that can be successfully treated medically.

Advanced cardiac imaging techniques assist in characterizing a cardiac mass and directing management

Advanced imaging techniques, including contrast echocardiography and CMR, provided valuable characterization and evaluation of a boy with an unusual cardiac mass. Imaging features assisted with differentiation of benign from malignant etiology and excluding thrombus. Accurate imaging techniques saved our patient risks associated with unnecessary surgery or anticoagulation. The ability to accurately define size serially assisted in guiding expectant management. He died from a noncardiac cause at age 28, and autopsy demonstrated a hamartoma of mature cardiac myocytes.