Intramachine and intermachine variability in transesophageal color doppler images of pulsatile jets: in vitro studies

Background: Color Doppler flow mapping is widely used as a marker of severity of valvular regurgitation, and the transesophageal approach has provided high-quality images in patients with poor acoustic windows. However, different instruments produce significantly variable images. Techniques that use jet spatial information to determine the severity of the lesion may need to be derived specifically for the instrument used. Given a lack of standardization of the many commonly used instruments, the goal of this study was to quantify variability between instruments by imaging well-defined jet flow fields created in vitro. Methods and Results: Pulsatile jets were created in vitro using a blood analogue fluid through physiological orifice diameters and imaged from a distal window using six commonly used color Doppler instruments. Transesophageal transducers (5.0 MHz) were used with all instruments studied. Peak jet areas were planimetered and averaged with systematic variations in Nyquist limit, color filter, and sector angle (which produced variations in frame rate). Changes in instrument settings produced significant variation in jet size for all instruments studied. Comparisons within instruments and among instruments were difficult because of preset and ambiguous setting levels. When comparisons were possible between similar settings, variability was dramatic (eg, 57% variability between instruments with very similar Nyquist limits). Conclusions: A lack of standardized color Doppler instrument settings prohibits translation of jet area techniques from one instrument to another. This should be taken into consideration when using different machines for clinical study

Hypertensive Cardiomyopathy: Diagnostic Approach and Clinical Differentiation from Hypertrophic Cardiomyopathy

Hypertensive Cardiomyopathy (HTN-CM) is a structural cardiac disorder generally accompanied by concentric or eccentric Left Ventricular Hypertrophy (LVH) associated with diastolic or/and systolic dysfunction in patients with persistent systemic hypertension. It occurs in the absence of other cardiac diseases capable of causing myocardial hypertrophy or cardiac dysfunction. Long standing arterial hypertension (HTN) leads to structural and functional myocardial abnormalities resulting in myocardial ischemia, fibrosis, and hypertrophy. HTN-CM is predominantly a disease of impaired relaxation rather than impaired contractility, although subtle myocardial systolic abnormalities could be detected recently by Global Longitudinal Systolic Strain (GLS) Speckle Tracking Echocardiography (STE). Importantly, the accompanying LVH is itself a risk factor for mortality and morbidity and is considered an independent predictor for Sudden Cardiac Death (SCD). Therefore, early detection of LVH development in patients with Hypertensive Hypertrophic Cardiomyopathy (HTN-CM) is crucial for optimal treatment. In addition to pathological findings, echocardiography and cardiac magnetic resonance imaging are ideal tools for the diagnosis of HTN-CM and can differentiate it from Hypertrophic Cardiomyopathy (HCM). Timely diagnosis of this condition and utilization of appropriate treatment are required to improve morbidity and mortality in hypertensive patients. This review presents an overview of utilization of multidisciplinary imaging modalities approach for proper diagnosis of HTN-CM and its differentiation from HCM. Relevant article highlighted key points in differentiation of HTN-CM from HCM and the effects of hypertension on cardiac hypertrophy and heart failure development are discussed in clinical case study

Updates Regarding Prediction and Prevention of Sudden Cardiac Death

Sudden cardiac death (SCD) remains a major public health problem globally, especially in the United States causing more than 300,000 deaths annually. SCD from cardiac arrest is the most common cause of death worldwide, accounting for >50% of all deaths from cardiovascular diseases (CVDs) and it is characterized by unexpected collapse due to an underlying cardiovascular cause. The condition usually results from an electrical disturbance in the heart that disrupts its pumping action, stopping blood flow to the body. When the heart stops, the lack of oxygenated blood can causes death or permanent brain damage within minutes. Time is extremely critical when someone or a clinician is helping an unconscious person who is not breathing. SCD represents a major challenge for the clinician because most episodes occur in individuals without previously known cardiac disease. Hence, an early prediction of individuals at risk of SCD is the holly-grail of all physicians. Because most individuals experiencing SCD currently are not identifiable as being at high risk, community-based public access to defibrillation programs is essential to save lives and more so to improve neurological and functional outcomes for cardiac arrest victims. In order to prevent SCD, it is imperative to impose an aggressive management of cardiovascular risk factors, including performing exercise regularly, educating patients about the dangers of CVDs, promoting a healthy diet, restricting consumption of sugar, saturated fat, salt and smoking cessation to promote a heart healthy behavior to all, young children in particular. Finally, a preclinical prediction of patients at risk of SCD and early detection of the disease is crucial for early intervention and definitely will reduce the incidence of sudden cardiac death dramatically

Prediction of Preclinical Myocardial Dysfunction among Obese Diabetics with Preserved Ejection Fraction Using Tissue Doppler Imaging and Speckle Tracking Echocardiography

Background. Obesity and type 2 diabetes mellitus (T2DM) are two interrelated and preventable disorders. However, they are responsible for significant global mortality from cardiovascular diseases (CVDs). Clinical studies have demonstrated that global longitudinal strain (GLS) using speckle tracking echocardiography (STE), can assess myocardial function accurately in apparently, healthy patients with diabetes and obesity in the settings of acute and chronic ischemia and suspected cardiomyopathy without heart failure. No such studies have been published to date regarding subclinical detection of cardiac dysfunction among obese patients with T2DM. This study aims to investigate the role of STE in the early pre-clinical diagnosis of impairment of diastolic and systolic dysfunction in obese patients with T2DM. This study also investigated whether it is possible to detect early pre-clinical impairment of diastolic and systolic dysfunction in obese T2DM patients, via Tissue Doppler Imaging (TDI), maximum rate of left ventricular pressure development (peak dP/dt) and GLS using STE for comparison. Subjects and Methods. After clearance from the review board of Dibba- Hospital, Alfujairah, UAE, all the available records of patients with the diagnosis of obesity and diabetes were examined. The study included 214 patients presenting with obesity in conjunction with diabetes and 93 age-matched healthy control subjects. STE was performed among all the patients and subjects along with Tissue Doppler Imaging (TDI). This study assessed maximal rate of pressure rise during ventricular contraction (peak dP/dt) and global longitudinal strain (GLS) using STE methods. Transthoracic echocardiography, myocardial Doppler-derived systolic (sm), early diastolic velocity (em) and GLS were also obtained, among all the subjects. Results. The results show that cardiac functions via conventional echocardiography (CE) were similar in the 2 groups. Using TDI and conventional mitral Doppler flow, obese subjects with diabetes showed an evidence of diastolic function abnormalities in the form of lower Ea velocity (9.5 ± 2.9 vs. 18.4 ± 3.5 cm/s, p < 0.0001), an increased Aa velocity (16.5 ± 2.4 vs. 14.1 ± 2.2 cm/s p < 0.05), higher left ventricular filling pressure (E/Ea = 12 ± 4.4 vs 8±3.1), p 35) (n = 26) had reduced LV systolic and diastolic function compared with healthy controls. Regarding, systolic function indices, the findings revealed lower average longitudinal peak systolic strain, sm and reduced em, although, LV ejection fraction remained normal (56.48% ± 8.81). Among subjects with severe obesity (n = 26), the findings reveal that global longitudinal presystolic strain (GLPSS) is highly correlated with maximum rate of pressure development of LV (dp/dt), although the LVEF remained normal, in comparison to systolic strain and dp/dt. (.5% ±1.4 vs -19.54% ± 4.5; p < 0.001), in the age-matched healthy subjects. However, the frequency/grade of DCM detected by STE, among patients having obesity with T2DM, correlated closely with the degree of obesity, metabolic abnormalities and clustering of other major risk factors, especially high blood pressure. The findings also revealed that chest pain due to coronary heart disease (CAD), dyspnea and DCM were more common among female patients compared to men. Conclusion. The results indicate that patients having obesity with T2DM should be advised to undertake early TDI and STE for early diagnosis of decreased cardiac diastolic and systolic dysfunctions and cardiomyopathy, which is likely to be missed by conventional echocardiography. Significant differences in regional and global strain were also identified between the severely obese diabetic (BMI ≥ 35), (GLPSS (-13) patients compared to less obese subjects

Simulation for transthoracic echocardiography of aortic valve

Simulation allows interactive transthoracic echocardiography (TTE) learning using a virtual three-dimensional model of the heart and may aid in the acquisition of the cognitive and technical skills needed to perform TTE. The ability to link probe manipulation, cardiac anatomy, and echocardiographic images using a simulator has been shown to be an effective model for training anesthesiology residents in transesophageal echocardiography. A proposed alternative to real-time reality patient-based learning is simulation-based training that allows anesthesiologists to learn complex concepts and procedures, especially for specific structures such as aortic valve

Clinical Usefulness of Three-Dimensional Echocardiography

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Echocardiographic evaluation of mitral valve regurgitation

Echocardiography is the primary imaging modality for the evaluation of mitral valve regurgitation. A comprehensive assessment of mitral regurgitation using different echocardiographic techniques provides important information regarding the etiology and severity of mitral regurgitation and its consequences on cardiac function. In addition, echocardiography plays an important role in the management of patients with mitral regurgitation