Myocardial Thickness Research Articles

Anatomical indicators of the heart and coronary arteries: An anthropometric study

Introduction: Previous studies confirm that there is no anthropometric index of normal Iranian hearts, including diameter of cardiac valve, thickness of myocardial septum and coronary artery variation. The purpose of this study was to assess the anatomical indexes of the human heart and coronary artery in the Iranian population.
 Methods: The study was performed with 207 adult human hearts in both sexes (182 male and 25 female), fixed in 10% formaldehyde. Myocardial thickness and diameter of heart valves were measured using a Vernier caliper. Assessments of the coronary artery were carried out after removal of the pericardium.
 Results: Analysis of 207 cadaver coronary arteries showed left coronary artery (LCA) dominance type was present in 6.3% of corpus, and balance was present in 4.3% of corpus, while the largest number (89.4%) had right coronary artery (RCA) dominance. The mean values of the morphometric data are as follows: right atrial wall thickness (2.08 +/- 0.04 mm), left atrial wall thickness (2.08 +/- 0.04 mm), interatrial wall thickness (4.92 +/- 0.08 mm), right ventricular wall thickness (3.35 +/- 0.05 mm), left ventricular wall thickness (8.36 +/- 0.13 mm), interventricular wall thickness (12.01 +/- 0.2 mm), diameter of the aorta (23.6 +/- 0.4 mm), diameter of the pulmonary artery (24.94 +/- 0.4 mm), large diameter of the mitral valve (34.16 +/- 0.27 mm), and large diameter of the tricuspid valve (38.8 +/- 0.24 mm).
 Conclusion: The anatomical knowledge of cardiac indicators and coronary artery data will be helpful and clinically relevant, especially for cardiac surgeons for coronary artery bypass grafting and coronary arteriography.

Understanding and recognizing cardiac amyloidosis.

Cardiac amyloidosis is an infiltrative abnormality that causes myocardial thickening and dysfunction. Historically, it has been underrecognized as a cause of heart failure and was often misdiagnosed. In the past decade, the cardiology community has improved the understanding of the subtypes of these protein-based infiltrates and how they play a role in heart failure. This article reviews the pathophysiology, presentation, diagnosis, and management of cardiac amyloidosis.

Quantification of defect contrast in microSPECT imaging of a myocardial phantom

Ischemic heart disease remains a significant public health concern, accentuating the importance of basic research and therapeutic studies of small animals in which myocardial changes can be reproducibly detected and quantified. Few or no studies have investigated the performance of microSPECT in quantifying myocardial lesions. We utilized three versions of a multi-compartment phantom containing two left ventricular myocardial compartments (one uniform and one with a transmural ‘cold’ defect), a ventricular blood pool, and a background compartment, where each version had a different myocardial wall thickness (0.75, 1.0 and 1.25 mm). Each compartment was imaged separately while acquiring list-mode data. The separate compartment data were manipulated into a single data set with a known defect contrast, blood-pool and background activity. Data were processed with background-free defect-contrast values of 0 (no defect), −0.25, −0.5, −0.75, and −1.0 (all defect), three ratios of blood-pool to myocardial activity, 0 (no blood pool activity), 0.1, and 0.2 (20% of the activity in the healthy myocardial compartment), and three ratios of uniform background 0 (no background activity), 0.1 and 0.2, relative to the healthy myocardial compartment. For each wall thickness, defect contrast, blood-pool, and background activity combination, 25 list-mode noise realizations were generated and reconstructed. Volumes of interest were drawn and used to determine mean contrast recovery coefficients (CRCs) over the noise ensembles. We developed a slope-analysis procedure to estimate a single CRC over all contrast levels, with resulting CRC values (for no blood-pool and no background) of 0.848, 0.946, and 0.834 for the 0.75, 1.0, and 1.25 mm wall thicknesses, respectively. We also determined and validated a reprocessing method to calculate an ideal CRC. This work demonstrates the quantitative abilities of microSPECT for myocardial-defect imaging utilizing CRC and establishes a framework for evaluating defect-imaging capabilities in other systems.

Accuracy and clinical feasibility of 3D-myocardial thickness map measured by cardiac computed tomogram

BackgroundAlthough myocardial thickness is an important variable for therapeutic catheter ablation of cardiac arrhythmias, quantification of wall thickness has been overlooked. We developed a software (AMBER) that measures 3D-myocardial thickness using a cardiac computed tomogram (CT) image, verified its accuracy, and tested its clinical feasibility.MethodsWe generated 3D-thickness maps by calculating wall thickness (WT) from the CT images of 120 patients’ hearts and a 3D-phantom model (PhM). The initial vector field of the Laplace equation was oriented to calculate WT with the field lines derived from the 3D mesh. We demonstrate the robustness of the Laplace WT algorithm by comparing with the real thickness of 3D-PhM, echocardiographically measured left ventricular (LV) WT, and regional left atrial (LA) WT reported from previous studies. We conducted a pilot case of catheter ablation for atrial fibrillation (AF) utilizing real-time LAWT map-guided radiofrequency (RF) energy titration.ResultsAMBER 3D-WT had excellent correlations with the real thickness of the PhM (R = 0.968, p < 0.001) and echocardiographically measured LVWT in 10 patients (R = 0.656, p = 0.007). AMBER 3D-LAWT (n = 120) showed a relatively good match with 12 previously reported regional LAWT. We successfully conducted pilot AF ablation utilizing AMBER 3D-LAWT map-guided real-time RF energy titration.ConclusionWe developed and verified an AMBER 3D-cardiac thickness map measured by cardiac CT images for LAWT and LVWT, and tested its feasibility for RF energy titration during clinical catheter ablation.

Left Ventricular Mass Assessment by 1- and 2-Dimensional Echocardiographic Methods in Hemodialysis Patients: Changes in Left Ventricular Volume Using Echocardiography Before and After a Hemodialysis Session

Rationale & ObjectiveLeft ventricular (LV) mass (LVM) is a predictor of cardiovascular morbidity and mortality and commonly calculated using 1-dimensional (1D) echocardiographic methods. These methods are vulnerable to small measurement errors and LVM may wrongly change according to changes in LV volume (LVV). Less commonly used 2-dimensional (2D) methods can accommodate to the changes in LVV and may be a better alternative among patients receiving hemodialysis (HD) with large fluid fluctuations.Study DesignObservational study.Setting & ParticipantsPatients with end-stage kidney disease receiving HD.ExposureOne HD session.Analytical ApproachTransthoracic echocardiography was performed right before and after HD. LVM was calculated using 1D (Devereux, Penn, and Teichholz) and 2D methods (truncated ellipsoid and area-length).OutcomesSignificant differences in LVM after HD.ResultsWe compared dimensions, LVV and LVM, in 53 patients (mean age, 63 ± 15 years; 66% men). For each 1-L increase in ultrafiltration volume (UFV), LV internal diameter decreased 1.1 mm (95% CI, 0.5-1.7 mm; P = 0.001). Patients were divided into 2 groups by the median UFV of 1.6 L. Patients with UFV > 1.6 L had significant smaller LVV and LV internal diameter after HD. LVM calculated using 1D methods decreased according to changes in LVV. Conversely, LVM calculated using 2D methods was not significantly different after HD. No significant change in differences between diastolic − systolic myocardial thickness or LVM as assessed using 1D and 2D methods was observed before and after HD, indicating that LVM remained constant despite HD.LimitationsWe did not use contrast enhancement, 3-dimensional methods, or cardiac magnetic resonance.ConclusionsLVM calculated using 2D methods, truncated ellipsoid and area-length, is less affected by fluctuations in fluid and LVV, in contrast to 1D methods. Complementary LVM calculation using 2D methods is encouraged, especially in patients with large fluid fluctuations in which increased LVM using a 1D method has been detected.

Impact of High-Power Short-Duration Radiofrequency Ablation on Long-Term Lesion Durability for Atrial Fibrillation Ablation.

The goal of this study was to compare lesion durability between high-power short-duration (HP-SD) and moderate-power moderate-duration (MP-MD) ablation strategies. HP-SD radiofrequency ablation (RFA) was developed to improve pulmonary vein isolation (PVI) by reducing the effect of catheter instability inherent to MP-MD ablation strategies. However, its long-term effect on lesion durability for the treatment of atrial fibrillation is unknown. Patients with atrial fibrillation (n=112) underwent PVI using HP-SD ablation (45 to 50 W, 8 to 15 s) with contact force-sensing open irrigated catheter. Cavotricuspid isthmus, mitral annular, and roof lines were permitted. A control group (n=112) underwent ablation using MP-MD ablation (20 to 40 W, 20 to 30 s) with similar technology. Chronic PV reconnection was examined in patients who required a redo procedure (HP-SD ablation, n=18; MP-MD ablation, n=23). The rate of PVI at the completion of the initial encirclement was similar between the HP-SD and MP-MD ablation strategies (90.2% vs. 83.0%; p=0.006). The HP-SD strategy required shorter RFA time (17.2 ± 3.4min vs. 31.1± 5.6min; p<0.001). The incidence of chronic PV reconnection was lower with HP-SD ablation (16.6% vs. 52.2%; p=0.03). Areas of chronic reconnection were associated with catheter motion≥1mm for≥50% application duration. In a higher proportion of HP-SD applications, catheter motion was<1mm during≥50% duration (88.6% vs. 72.8%; p<0.001), allowing energy delivery with greater stability. Both ablation strategies were effective for cavotricuspid isthmus; however, the HP-SD strategy was less effective for mitral annular lines, requiring ablation at lower power for longer duration to avoid steam pops. HP-SD ablation may improve PVI durability, and it shortens RFA time. However, ablation in thicker myocardium often requires lower power applied for longer duration, allowing deeper lesions without tissue overheating.

The application of current diagnostic criteria for left ventricular noncompaction in patients undergoing cardiac MRI

Background: Isolated noncompaction of the left ventricular myocardium (INVM) is a cardiomyopathy characterized by an excessive number of prominent trabeculations with deep intertrabecular recesses in the left ventricular apex. IVNM is commonly diagnosed by echocardiography utilizing the Chin, Jenni, and Stollberger criteria. Cardiac magnetic resonance imaging (CMR) represents an additional modality which can diagnose IVNM. As with echocardiography, multiple diagnostic criteria have been proposed, including maximum end-diastolic non-compacted to compacted myocardial thickness ratio of >2.3, trabeculated LV mass >20% global LV mass, and increased fractal dimension. Furthermore, studies …

Residual Stress Estimates from Multi-cut Opening Angles of the Left Ventricle

PurposeResidual stress tensor has an essential influence on the mechanical behaviour of soft tissues and can be particularly useful in evaluating growth and remodelling of the heart and arteries. It is currently unclear if one single radial cut using the opening angle method can accurately estimate the residual stress. In many previous models, it has been assumed that a single radial cut can release the residual stress in a ring of the artery or left ventricle. However, experiments by Omens et al. (Biomech Model Mechanobiol 1:267–277, 2003) on mouse hearts, have shown that this is not the case. The aim of this paper is to answer this question using a multiple-cut mathematical model.MethodsIn this work, we have developed models of multiple cuts to estimate the residual stress in the left ventricle and compared with the one-cut model. Both two and four-cut models are considered. Given that the collagen fibres are normally coiled in the absence of loading, we use the isotropic part of the Holzapfel-Ogden strain energy function to model the unloaded myocardium.ResultsThe estimated residual hoop stress from our multiple-cut model is around 8 to 9 times greater than that of a single-cut model. Although in principle infinite cuts are required to release the residual stress, we find four cuts seem to be sufficient as the model agrees well with experimental measurements of the myocardial thickness. Indeed, even the two-cut model already gives a reasonable estimate of the maximum residual hoop stress. We show that the results are not significantly different using homogeneous or heterogeneous material models. Finally, we explain that the multiple cuts approach also applies to arteries.ConclusionWe conclude that both radial and circumferential cuts are required to release the residual stress in the left ventricle; using multiple radial cuts alone is not sufficient. A multiple-cut model gives a marked increase of residual stress in a left ventricle ring compared to that of the commonly used single-cut model.

Evaluation of left ventricular strain in patients with arrhythmia based on the 3T MR temporal parallel acquisition technique

Most of the current studies on myocardial strain are mainly applied in patients with sinus rhythm because the image quality of arrhythmias obtained with conventional scanning sequences does not meet diagnostic needs. Here, we intend to assess left ventricular (LV) global myocardial strain in patients with arrhythmias with 3 Tesla magnetic resonance (MR) and a new cine sequence. Thirty-three patients with arrhythmia and forty-eight subjects with sinus rhythm were enrolled in the study. LV myocardial thickness, cardiac function, myocardial strain and the apparent contrast-to-noise ratio (CNR) were all measured and compared using images generated by the real-time temporal parallel acquisition technique (TPAT) and the conventional cine sequence. In the arrhythmia group, the image quality of real-time TPAT was significantly better than that of the conventional cine sequence. In the arrhythmia group, the LV global peak radial strain and global peak circumferential strain values of real-time TPAT were significantly different from those of the conventional technique (radial strain, conventional: 20.27 ± 15.39 vs. TPAT: 24.14 ± 15.85, p = 0.007; circumferential strain, conventional:−12.06 ± 6.60 vs. TPAT: −13.71 ± 6.31, p = 0.015). There was no significant difference in global peak longitudinal strain between real-time TPAT and the conventional technique (−10.94 ± 4.66 vs. −10.70 ± 5.96, p = 0.771). There was no significant difference in the cardiac function parameters between the two techniques (p > 0.05), but there was a significant difference in 12 segments of the LV wall thickness between the two sequences (p < 0.05). In the sinus rhythm group, image quality using real-time TPAT was comparable to that using the conventional technique, and there was no significant difference in any of the indices (p > 0.05). Real-time TPAT is an effective method for detection of left ventricular myocardial deformation in patients with arrhythmia.

The sensitivity of DPD scintigraphy to detect transthyretin cardiac amyloidosis in V30M mutation depends on the phenotypic expression of the disease

Background: There is a growing need for a non-invasive test to detect cardiac involvement in patients with transthyretin-related hereditary amyloidosis (ATTR) caused by V30M mutation. 99mTc-3,3-diphosphono-1,2-propanodicarboxylic acid (DPD) scintigraphy is a promising method, but its accuracy in this particular mutation remains unknown.Methods: A cohort of 179 patients: 92 with early-onset disease (EoD, symptoms <50-years-old), 33 with late-onset disease (LoD) and 54 asymptomatic carriers were prospectively evaluated and underwent DPD scintigraphy, which was compared with the results of echocardiogram, ambulatory blood pressure monitoring, 24 h-Holter, myocardial 123I-metaiodobenzylguanidine imaging and NT-proBNP.Results: Amyloid cardiomyopathy, defined as septal thickness ≥13 mm, was present in 32 patients (17.9%) and was more frequent in those with LoD (OR: 3.68, p = .003). Cardiac DPD uptake was present in 22 individuals (12.3%) and correlated with parameters indicative of cardiac amyloidosis. DPD imaging was strongly influenced by the age of disease onset: among patients with myocardial thickening, cardiac DPD retention was present in 11/15 (73.3%) with LoD, in contrast to only 4/17 (26.7%) with EoD (p = .005). Two patients with myocardial thickening and normal DPD scintigraphy underwent endomyocardial biopsy that confirmed ATTR amyloidosis.Conclusion: DPD scintigraphy presents suboptimal sensitivity to detect cardiac involvement in ATTRV30M, particularly in symptomatic patients with EoD.

Small Animal Review

Summary: In feline hypertrophic cardiomyopathy the increase in myocardial thickness and cardiac weight in some cases is due to diffuse expansion of the interstitium by granulation tissue as a consequence of cardiomyocyte degeneration, probably associated with infarcts, and is not necessarily the result of true myocardial hypertrophy.

1320Effectiveness of atrial flutter ablation line selection using SOUNDSTAR catheter

Abstract Background Cavotricuspid isthmus (CTI) ablation for atrial flutter (AFL) shows a high success rate and effective for patients. However, operators experience difficulties in CTI ablation in some cases and need additional ablation for repeated recurrence. We investigated whether the SOUNDSTAR® (Biosense. Webster, Diamond Barr, CA, USA) catheter would be effective to select a CTI line of high therapeutic effect. Methods We have investigated the anatomy of around CTI by SOUNDSTAR® catheter and decided the CTI line using the anatomical information in AFL ablation (Figure1). We assumed two CTI lines of medial and lateral line. Medial CTI (M-CTI) line was more common and shorter line. Lateral CTI (L-CTI) line was uncommon and slightly longer line. We use 3.5mm tip catheter with NxT steerable introducer. The target Ablation Index (AI) was 400, and the target VisTtag™ interval was 6 mm or less. Results A total 30 of AFL ablated cases were investigated retrospectively. We surveyed 15 cases in M-CTI group and 15 cases in L-CTI group. Comparing the length of CTI in all cases, the length of M-CTI line was shorter than L-CTI line (M-CTI 32.1 ± 6.6mm vs. L-CTI 38.4 ± 8.3mm, n = 30, p &amp;lt;0.01). The atrial wall thickness of midsection and tricuspid valve (TV) side were thicker in M-CTI line (Midsection: M-CTI 4.0 ± 1.2mm vs. L-CTI 3.3 ± 0.8mm, n = 30, p &amp;lt;0.05, TV side: M-CTI 5.4 ± 1.4mm vs. L-CTI 4.3 ± 1.1mm, n = 30, p &amp;lt;0.05,). There was no difference in the required number of points to complete initial line (M-CTI 8.4 ± 1.6 vs. L-CTI 8.1 ± 1.7, n = 15, ns). Eustachian ridge in IVC side was thicker and higher in the M-CTI group (3.4 ± 3.3mm vs. 0.9 ± 1.9mm, n =30, p &amp;lt;0.01) and ablation on the Eustachian ridge showed instability of catheter placement. A lot of RF delivery was required on Eustachian ridge in M-CTI (2.6 ± 0.6 vs. 2.1 ± 0.7, n =15, p &amp;lt;0.05) and AI had resulted lower in M-CTI (351 ± 42.8 vs. 381 ± 27.1, n =15, p &amp;lt;0.05). Recurrence is more common in M-CTI group (9/15, 60% vs. 3/15, 20%). Recurrence sites in M-CTI group were distributed ((IVC side 3/9 (33%), midsection 5/9 (56%), TV side 5/9 (56%)) and multiple recurrences occurred in 3/9 (33%). Recurrence sites in L-CTI were only midsection of CTI (3/3, 100%). Conclusions CTI ablation at the shorter distance M-CTI, which is commonly selected, resulted in more recurrences due to the unevenness including Eustachian ridge and the myocardium thickness. However, ablation at slightly longer L-CTI line showed lower recurrence and effective for CTI ablation. Abstract Figure 1

Role of fetal echocardiography in morphologic and functional assessment of fetal heart in diabetic mothers

BackgroundDiabetes mellitus (DM) is the commonest medical disorder faced during pregnancy and it includes type I, type II, and gestational diabetes. It may predispose to various complications including fetus malformation, macrosomia, spontaneous abortion, stillbirth, neonatal death, and intrauterine growth retardation. Hypertrophic cardiomyopathy (HCM) is one of the common anomalies depicted with diabetes. Fetal cardiac function analysis might provide important information on the hemodynamic status and cardiac adaptation to different perinatal complications.ResultsThe mean septal thickness in the diabetic group was 0.7163 ± 0.1746 cm and 0.4989 ± 0.08068 cm in the control group. The mean myocardial thickness of the right ventricular free wall in the diabetic group was 0.6532 ± 0.13792 cm and 0.4874 ± 0.07482 cm in the control group. The mean myocardial thickness of the left ventricular free wall in the diabetic group was 0.6437 ± 0.13421 cm and 0.4737 ± 0.07573 cm in the control group. The mean value of myocardial performance index (Tie Index) in the diabetic group was 0.6232 ± 0.15606 and 0.4626 ± 0.04357 in the control group.ConclusionFrom our study, we can conclude that prenatal complete echocardiographic study should be mandatory in fetuses of diabetic mothers due to high risk of congenital heart defects and onset of hypertrophic cardiomyopathy with fetal cardiac function impairment in the third trimester.Early diagnosis of congenital heart defects as well as evidence of hypertrophic cardiomyopathy and fetal cardiac function impairment that occurs in fetuses of maternal diabetes will definitely guide prompt postnatal therapy and care for those neonates.

Evaluation of N-terminal prohormone of brain natriuretic peptide and cardiac troponin-I levels in cats with systolic anterior motion of the mitral valve in the absence of left ventricular hypertrophy

ObjectivesTo identify the prevalence of systolic anterior motion of the mitral valve (SAM) in apparently healthy cats in the absence of left ventricular hypertrophy (LVH) and examine the relationship between specific cardiac biomarker concentrations and echocardiographic parameters in these individuals. Animalseighty client-owned cats. Materials and methodsretrospective study; inclusion criteria were the presence of SAM on conscious echocardiography and concurrent measurement of plasma N-terminal prohormone of brain natriuretic peptide (NT-proBNP) and serum cardiac troponin-I (cTnI). Cats were excluded if they had LVH, left atrial enlargement or systemic disease. The percentages of cats with NT-proBNP and cTnI concentrations above the normal reference range were calculated. The correlation between each biomarker concentration and left ventricular myocardial wall thickness, left atrial size and maximum left ventricular outflow tract velocity was evaluated. ResultsThirty-four of 80 patients with SAM showed no evidence of cardiac remodelling (LVH or left atrial enlargement). Of these patients, 30 of 34 had elevated NT-proBNP, and cTnI was elevated in 13 of 27 (48.1%) cats where this biomarker was measured in association with the NT-proBNP assay. A positive correlation was observed between concentration of plasma NT-proBNP and maximum left ventricular outflow tract velocity (rs = 0.67, p<0.0001). No significant correlations were found between the concentration of biomarkers and the remaining echocardiographic parameters. ConclusionsSAM is frequently observed in cats even in the absence of cardiac remodelling, and these individuals often demonstrate elevated plasma NT-proBNP and serum cTnI concentrations. Plasma NT-proBNP elevation is correlated with the severity of the left ventricular outflow obstruction caused by SAM.

Epidemiological and pathological aspects of cardiomyopathies in cats in southern Brazil

ABSTRACT: Cardiomyopathies are considered one of the most important causes of heart failure in cats and are subdivided into three main morphological types: hypertrophic (HCM), dilated (DCM), and restrictive (RCM). This study aimed to determine the frequency and types of cardiomyopathies in cats diagnosed in southern Brazil, with an emphasis on their epidemiological and pathological aspects. Necropsy reports filed in a veterinary pathology laboratory were reviewed, and cats diagnosed with cardiomyopathy were selected for the study. Animal identification data, history and clinical signs, and gross lesions, were reviewed and compiled. During the study period, 1.594 cat necropsies were performed, of which 72 (4.5%) comprised a diagnosis of cardiomyopathy. HCM was the most frequent followed by CMR and CMD, representing 77.8%, 12.5% and 9.7%, respectively. Age ranged from three months to 18 years, with a median age of seven years. In relation to sex, 62.5% were males and 37.5% females. In 76.4% of the cases, it affected cats without a breed defined. Restrictive mixed dyspnea and hydrothorax were the main signs or findings of the clinical examination. Sudden death and acute paresis of the pelvic limbs due to aortic thromboembolism have also been described. In HCM, myocardial thickening was observed, with a reduction in the ventricular chamber. Hypertrophy, disarray, and fibrosis of the myofibers were the main histological findings. In RCM, whitish and thickened endocardium was seen in most cases. DCM was characterized by dilated cardiac chambers, and microscopic examination revealed no significant findings. The main extra cardiac lesions revealed pulmonary edema and congestion, hydrothorax and chronic passive congestion of the liver. Cardiomyopathies are important causes of death in cats and should be included in the differential diagnosis of patients with cardio respiratory clinical signs and in cases related to sudden death and acute paresis of the pelvic limbs.

“Apical thinning”: Relations between myocardial wall thickness and apical left ventricular tracer uptake as assessed with positron emission tomography myocardial perfusion imaging

BackgroundA reduction in left ventricular apical tracer uptake (apical thinning) is frequently observed in myocardial perfusion imaging (MPI), yet its cause remains a matter of debate, particularly in perfusion emission tomography (PET). This analysis sought to determine whether apical thinning in PET-MPI is attributable to true anatomical thinning of the left ventricular apical myocardium. Methods and ResultsWe retrospectively analyzed 57 patients without any history or signs of apical myocardial infarction who underwent rest PET-MPI with 13N-ammonia and contrast-enhanced cardiac computed tomography (CT). Semi-quantitative normalized percent apical 13N-ammonia uptake at rest, myocardial blood flow (MBF), and k2 wash-out rate constants were compared to apical myocardial wall thickness measurements derived from CT and base-to-apex gradients were calculated. Apical thinning was found in 93% of patients and in 74% when analysis of normalized apical tracer uptake was confined to end-systole. No significant correlation was found between apical myocardial thickness and apical tracer uptake (r = − 0.080, P = .553), MBF (r = − 0.211, P = .115), or k2 wash-out rate (r = − 0.023, P = .872), nor between apical myocardial thickness and any gradients. A statistically significant but small difference in apical myocardial thickness was observed in patients with moderately to severely reduced apical tracer uptake vs patients with normal to mildly reduced uptake (4.3 ± 0.7 mm vs 4.7 ± 0.7 mm; P = .043). ConclusionsApical thinning is a highly prevalent finding during 13N-ammonia PET-MPI that is not solely attributable to true anatomical apical wall thickness or the partial volume effect. Other factors that yet need to be identified seem to have a more prominent impact.

Оцінка факторів ризику смерті від кардіогенного набряку легень у котів за різних форм кардіоміопатій

Abstract. One of the most common causes of death in cats with cardiomyopathy is pulmonary edema. Different forms of feline cardiomyopathies can have a diverse clinical signs. The onset of clinical signs is often related to recent stressful situation such as visiting a clinic or transportation. It is unknown how to identify animals which are predisposing to pulmonary edema and death. The evaluation of literary datahas confirmed that there are insufficient researches in this area. Also it is reliably unknown, which changes in clinical status or on ECHO could be markers of death in cats at cardiogenic pulmonary edema. This article is highlights the topic of estimation of risk assessment of death in cats in case of cardiogenic pulmonary edema. All types of cardiomyopathies were diagnosed in this study. We included cats whose owners addressed the clinic complaining of dyspnoea and worsening of activity. An echocardiographic and radiological examination was performed in the clinic. The authors paid attention to the following markers: the degree of radiological changes in pulmonary parenchyma, data of clinical examinations, the degree of changes of left ventricular and the size of left atrium. It was found that main marker of death in cats at cardiogenic pulmonary edema is the left atrium to aorta more then 2,2. Severe changes in lung parenchyma on X-ray and decrease in left ventricular systolic function also increase the risk of cardiac death in acute heart failure. Left ventricular myocardial thickness and the presence of spontaneous contrast do not affect survival during the first days of hospitalization. M ost likely, these changes have more impact on overall life expectancy . . Keywords: domestic cat, hypertrophic cardiomyopathy, restrictive cardiomyopathy, interstitial pattern, cardiogenic pulmonary edema

Analysis of three-chamber view conventional and tagged cine MRI in patients with suspected hypertrophic cardiomyopathy.

To investigate the potential value of adding a tagged three-chamber (3Ch) cine to clinical hypertrophic cardiomyopathy (HCM) magnetic resonance imaging (MRI) protocols, including to help distinguish HCM patients with regionally impaired cardiac function. Forty-eight HCM patients, five patients with "septal knuckle" (SK), and 20 healthy volunteers underwent MRI at 1.5T; a tagged 3Ch cine was added to the protocol. Regional strain, myocardial wall thickness, and mitral valve leaflet lengths were measured in the 3Ch view. In HCM, we found a reduced tangential strain with decreased diastolic relaxation in both hypertrophied (p = 0.003) and remote segments (p = 0.035). Strain in the basal septum correlated with the length of the coaptation zone + residual leaflet (r = 0.48, p < 0.001). In the basal free wall, patients with SK had faster relaxation compared to HCM patients with septal hypertrophy. The 3Ch tagged MRI sequence provides useful information for the examination of suspected HCM patients, with minimal additional time cost. Local wall function is closely associated with morphological changes of the mitral apparatus measured in the same plane and may provide insights into mechanisms of obstruction. The additional strain information may be helpful when analyzing local myocardial wall motion patterns in the presence of SK.

Cats with thermal burn injuries from California wildfires show echocardiographic evidence of myocardial thickening and intracardiac thrombi

Recent increases in the prevalence and severity of wildfires in some regions have resulted in an increased frequency of veterinary burn patients. Few studies exist regarding diagnostics and management of burn wounds in veterinary patients and current knowledge is extrapolated from human literature and research models. Post-burn cardiac injury is a common finding and predictor of mortality in human patients and echocardiography is an important tool in monitoring response to therapy and predicting outcome. We describe the notable findings from cats naturally exposed to California wildfires in 2017 and 2018. Domestic cats (n = 51) sustaining burn injuries from the Tubbs (2017) and Camp (2018) wildfires were prospectively enrolled and serial echocardiograms and cardiac troponin I evaluations were performed. Echocardiograms of affected cats revealed a high prevalence of myocardial thickening (18/51) and spontaneous echocardiographic contrast and thrombi formation (16/51). Forty-two cats survived to discharge and 6 died or were euthanized due to a possible cardiac cause. For the first time, we describe cardiovascular and coagulation effects of thermal burn and smoke inhalation in cats. Further studies in veterinary burn victims are warranted and serve as a translational research opportunity for uncovering novel disease mechanisms and therapies.

Paradoxical Higher Myocardial Wall Stress and Increased Cardiac Remodeling Despite Lower Mass in Females.

BackgroundIncreased left ventricular (LV) mass is characterized by increased myocardial wall thickness and/or ventricular dilatation that is associated with worse outcomes. We aim to comprehensively compare sex‐stratified associations between measures of LV remodeling and increasing LV mass in the general population.Methods and ResultsParticipants were prospectively recruited in the National Heart Center Singapore Biobank to examine health and cardiovascular risk factors in the general population. Cardiovascular magnetic resonance was performed in all individuals. Participants with established cardiovascular diseases and abnormal cardiovascular magnetic resonance scan results were excluded. Global and regional measures of LV remodeling (geometry, function, interstitial volumes, and wall stress) were performed using conventional image analysis and novel 3‐dimensional machine learning phenotyping. Sex‐stratified analyses were performed in 1005 participants (57% males; 53±13 years). Age and prevalence of cardiovascular risk factors were well‐matched in both sexes (P>0.05 for all). Progressive increase in LV mass was associated with increased concentricity in either sex, but to a greater extent in females. Compared with males, females had higher wall stress (mean difference: 170 mm Hg, P<0.0001) despite smaller LV mass (42.4±8.2 versus 55.6±14.2 g/m2, P<0.0001), lower blood pressures (P<0.0001), and higher LV ejection fraction (61.9±5.9% versus 58.6±6.4%, P<0.0001). The regions of increased concentric remodeling corresponded to regions of increased wall stress. Compared with males, females had increased extracellular volume fraction (27.1±2.4% versus 25.1±2.9%, P<0.0001).ConclusionsCompared with males, females have lower LV mass, increased wall stress, and concentric remodeling. These findings provide mechanistic insights that females are susceptible to particular cardiovascular complications.