Doppler tissue imaging in ST-elevation myocardial infarction

Highly available, noninvasive and cost-effective, echocardiography remains a keystone in the evaluation of patients with coronary artery disease (CAD). Echocardiographic assessment of cardiac function at rest and during dobutamine stress has direct clinical implications. Conventional echocardiographic parameters however, are partly based on visual interpretation of cardiac motion, thereby subject to interobserver variability, especially in patients with poor image quality. As a complement, myocardial velocity imaging techniques such as Doppler tissue imaging (DTI) offer quantitative markers of cardiac function. In the present study, we explored the feasibility and diagnostic value of DTI in the evaluation of left and right ventricular function, the presence of inducible ischemia and myocardial viability in patients with ST-elevation myocardial infarction (STEMI). In 90 patients with STEMI (64 men and 26 women aged 65±13 years) echocardiography was performed at day 1, 5–7 days and 6 months after admission. At day 5–7, dobutamine stress echocardiography (DSE) with wall motion analysis (WMA) was performed, followed by coronary angiography within 24 hours. Using DTI, systolic, early and late diastolic myocardial velocities were recorded near the mitral annulus at 4 left ventricular (LV) sites, and near the tricuspid annulus in the right ventricular free wall. The myocardial performance index (MPI), a Doppler-based, combined measure of systolic and diastolic function, was calculated as the sum of the isovolumic time intervals divided by the ejection time derived from DTI at the 4 LV sites. Forty-one aged-matched healthy subjects served as controls. In patients with complete normalization of conventional parameters of LV function at follow-up, peak systolic as well as early diastolic LV myocardial velocities were significantly reduced compared with those in healthy subjects, possibly reflecting a residual subendocardial damage. Using peak systolic velocity in the right ventricular (RV) free wall as a marker of RV function, sensitivity and specificity of DTI in identifying patients with electrocardographic signs of RV infarction (ST-elevation in ECG lead V4R) were 89% and 71%, respectively. Furthermore, peak RV systolic velocities remained reduced in patients with RV infarction, even after resolution of ECG changes and were still evident at 6 months’ follow-up. Use of the MPI as a marker of ischemia during DSE was shown to be feasible, and although the majority of patients did not achieve an optimal level of stress, relative changes in MPI between rest and peak stress offered reasonable diagnostic properties, superior to those of WMA. Sensitivity and specificity for detection of left anterior descending, left circumflex and right coronary artery disease were 80% and 87%, 59% and 80% and 85% and 72%, respectively. Finally, we found that MPI during low-dose dobutamine infusion exhibits a specific pattern, similar to that of WMA, predicting late recovery of LV systolic function. In conclusion, the use of DTI during echocardiography at rest and during dobutamine stress is feasible and allows evaluation of LV and RV function in the acute as well as the late phase after a STEMI. Furthermore, changes in MPI derived from DTI during DSE identify patients with residual CAD and predict late recovery of LV function, independently of age, troponin level and time to reperfusion treatment

No relationship between left ventricular radial wall motion and longitudinal velocity and the extent and severity of noncompaction cardiomyopathy

<p>Abstract</p> <p>Background</p> <p>Noncompaction cardiomyopathy (NCCM) is characterized by a prominent trabecular meshwork and deep intertrabecular recesses. Although systolic dysfunction is common, limited information is available on differences in wall motion of the normal compacted and noncompacted segments. The purpose of this study was to assess radial wall motion and longitudinal wall velocity in patients with NCCM, according to the extent and severity of noncompaction.</p> <p>Methods</p> <p>The study comprised 29 patients in sinus rhythm (age 41 ± 15 years, 15 men), who fulfilled stringent diagnostic criteria for NCCM and compared to 29 age and gender matched healthy controls. Segmental radial wall motion of all compacted and noncompacted segments was assessed with the standard visual wall motion score index and longitudinal systolic (Sm) wall velocity with tissue Doppler imaging of the mitral annulus. For each LV wall a normalized Sm value was calculated. The extent and severity of NC in each LV segment was assessed both in a qualitative and quantitative manner.</p> <p>Results</p> <p>Heart failure was the primary clinical presentation in half of the patients. NCCM patients had a wall motion score index of 1.68 ± 0.43 and a normalized Sm of 82 ± 20%. The total and maximal noncompaction scores were not related to the wall motion score index and the normalized Sm. NCCM patients with and without heart failure had similar total and maximal noncompaction scores.</p> <p>Conclusions</p> <p>In NCCM patient's radial wall motion and longitudinal LV wall velocity is impaired but not related to the extent or severity of noncompaction.</p

Echocardiography

The book "Echocardiography - New Techniques" brings worldwide contributions from highly acclaimed clinical and imaging science investigators, and representatives from academic medical centers. Each chapter is designed and written to be accessible to those with a basic knowledge of echocardiography. Additionally, the chapters are meant to be stimulating and educational to the experts and investigators in the field of echocardiography. This book is aimed primarily at cardiology fellows on their basic echocardiography rotation, fellows in general internal medicine, radiology and emergency medicine, and experts in the arena of echocardiography. Over the last few decades, the rate of technological advancements has developed dramatically, resulting in new techniques and improved echocardiographic imaging. The authors of this book focused on presenting the most advanced techniques useful in today's research and in daily clinical practice. These advanced techniques are utilized in the detection of different cardiac pathologies in patients, in contributing to their clinical decision, as well as follow-up and outcome predictions. In addition to the advanced techniques covered, this book expounds upon several special pathologies with respect to the functions of echocardiography

Cardiovascular imaging 2010 in the International Journal of Cardiovascular Imaging

Cardiovascular Aspects of Radiolog

Perspectives in noninvasive imaging for chronic coronary syndromes

Both the latest European guidelines on chronic coronary syndromes and the American guidelines on chest pain have underlined the importance of noninvasive imaging to select patients to be referred to invasive angiography. Nevertheless, although coronary stenosis has long been considered the main determinant of inducible ischemia and symptoms, growing evidence has demonstrated the importance of other underlying mechanisms (e.g., vasospasm, microvascular disease, energetic inefficiency). The search for a pathophysiology-driven treatment of these patients has therefore emerged as an important objective of multimodality imaging, integrating "anatomical" and "functional" information. We here provide an up-to-date guide for the choice and the interpretation of the currently available noninvasive anatomical and/or functional tests, focusing on emerging techniques (e.g., coronary flow velocity reserve, stress-cardiac magnetic resonance, hybrid imaging, functional-coronary computed tomography angiography, etc.), which could provide deeper pathophysiological insights to refine diagnostic and therapeutic pathways in the next future

Magnetic resonance imaging and its applicability in veterinary cardiology

Magnetic Resonance Imaging (MRI) is a technique whereby images are created by the manipulation of hydrogen atoms in magnetic fields; it is based on the principle of nuclear magnetic resonance (MR), which is non-invasive and non-ionising (Constantine, Shan, Flamm, & Sivananthan, 2004). Cardiac Magnetic Resonance Imaging (CMRI) uses the same principle: application of magnetic-field gradients that are adjusted to highlight desired tissue characteristics, producing a variety of sequences that allow detection of cardiac tissue and blood, and consequently anatomical and/or physiological abnormalities (Jeudy & White, 2008; Constantine et al., 2004). Basic pulse sequences used in CMRI are spin-echo and gradient-echo sequences, or their faster hybrids dark- or black-blood and bright-blood respectively (Constantine et al., 2004). CMRI is rapidly developing and is now an important diagnostic tool in human clinical cardiology (Gilbert, McConnell, Holden, Sivananthan, & Dukes-McEwan, 2010). In veterinary medicine the use of CMRI is still sporadic; its limitations in this field include the need for general anaesthesia, the cost and availability of the equipment, the steep learning curve to obtain and analyse the images, and the time needed to manually trace endocardial borders if semi-automated analysis is not available (MacDonald, Kittleson, Garcia-Nolen, Larson, & Wisner, 2006). CMRI was considered to be the reference method in many veterinary studies (Eskofier, Wefstaedt, Beyerbach, Nolte, & Hungerbuhler, 2015; Fattal et al., 2015; Sargent et al., 2015). Still, not many studies have been published or made available in this field. It is therefore essential to fully ascertain the clinical applications, advantages and limitations of CMRI in veterinary medicine. The aim of this review is to identify the potential applications of CMRI from a clinical point of view and compare it with echocardiography, which is still the gold standard in veterinary cardiology. We describe the principles and technique of MRI in small animal cardiology, and the diseases in which CMRI could be an important tool for diagnosis and prognosis

Cardiac resynchronization therapy; the importance of evaluating cardiac metabolism

Cardiac Dysfunction and Arrhythmia

Evaluation and prognostic significance of premature ventricular contractions in patients without structural heart disease

Introduction: Premature ventricular contractions (PVCs) are a common form of arrhythmia associated with poor prognosis in patients with structural heart disease. However, their prognostic impact on healthy individuals is unclear. There is also a lack of evidence about risk stratification of this group through cardiac imaging and electrocardiographic features. With this project we wanted to study whether patients with PVCs in which structural heart disease had thoroughly been excluded, have a worse prognosis than a control population. Moreover, we wanted to investigate whether PVC morphology and/or PVC duration are associated with the clinical outcome. Finally, we explored whether cardiac magnetic resonance imaging (CMR) and advanced echocardiographic parameters could unmask signs of structural heart disease in patients with high PVC-burden and normal echocardiogram. Methods: To study the prognostic impact of PVCs, we identified 807 patients with no history of structural heart disease, normal echocardiography and exercise test and verified PVCs. During a follow-up period of 5.2 years, we compared the clinical outcome–in terms of total mortality and cardiovascular morbidity–with a population matched by sex and age. To explore whether electrocardiographic features have a prognostic significance among healthy PVC-patients, we identified 541 patients to which we had access to PVC recording on 12-lead ECG and analysed PVC morphology and QRS width. For the studies focusing on diagnostic evaluation through advanced cardiac imaging, we included patients with a PVC burden of at least 10,000 beats/day and with normal results at exercise test and echocardiography. They underwent additional investigation with CMR (study 2) or advanced echocardiographic parameters that are normally not included in clinical praxis (study 3). Results: Healthy PVC-patients had a generally favourable prognosis, showing no worse clinical outcome than the sex- and age-matched control group that had not undergone investigation to rule out heart disease. However, patients with high PVC-burden showed signs of myocardial dysfunction when advanced imaging techniques were used, despite normal results at standard investigation that included echocardiogram. Sub-group analysis based on PVC-morphology showed that PVC originating from the outflow tract and the right ventricle was associated with a more favourable prognosis than intra cavity- and left ventricular PVCs respectively. Analysis of PVC-duration– measured as QRS-width during PVC–showed no impact on clinical outcome. Conclusions: PVC patients who had undergone a thorough medical examination with normal results did not have a worse outcome than matched controls during a median follow-up time of 5.2 years. PVC duration did not seem to be associated with the clinical outcome in our study including 541 patients with different sites of origin. However, PVCs with a morphology originating from the outflow tract and the right ventricle were associated with a better outcome. CMR and comprehensive advanced echocardiography could identify signs of myocardial dysfunction in patients with high PVC burden and normal findings at standard echocardiography. The clinical significance of these imaging findings needs to be assessed by larger longitudinal studies

A Non-Rigid Registration Method for Analyzing Myocardial Wall Motion for Cardiac CT Images

Cardiac resynchronization therapy (CRT) has a high percentage of non-responders. Successfully locating the optimal location for CRT lead placement on a priori images can increase efficiency in procedural preparation and execution and could potentially increase the rate of CRT responders. Registration has been used in the past to assess the motion of medical images. Specifically, one method of non-rigid registration has been utilized to assess the motion of left ventricular MR cardiac images. As CT imaging is often performed as part of resynchronization treatment planning and is a fast and accessible means of imaging, extending this registration method to assessing left ventricular motion of CT images could provide another means of reproducible contractility assessment. This thesis investigates the use of non-rigid registration to evaluate the myocardium motion in multi-phase multi-slice computed tomography (MSCT) cardiac imaging for the evaluation of mechanical contraction of the left ventricle