Mitral Annular Plane Systolic Excursion and Tricuspid Annular Plane Systolic Excursion in Cats with Hypertrophic Cardiomyopathy

Aortic annular plane systolic excursion in cats with hypertrophic cardiomyopathy

BACKGROUND

Impairment of left ventricular (LV) longitudinal function is an early marker of systolic dysfunction in hypertrophic cardiomyopathy (HCM). Aortic annular plane systolic excursion (AAPSE) is a measure of LV longitudinal function in people that has not been evaluated in cats.

HYPOTHESIS

Aortic annular plane systolic excursion is lower in cats with HCM compared to control cats, and cats in stage C have the lowest AAPSE.

ANIMALS

One hundred seventy-five cats: 60 normal, 61 HCM stage B and 54 HCM stage C cats.

MATERIALS

Multicenter retrospective case-control study. Electronic medical records from 4 referral hospitals were reviewed for cats diagnosed with HCM and normal cats. HCM was defined as LV wall thickness ≥6 mm and normal cats ≤5 mm. M-mode bisecting the aorta in right parasternal short-axis view was used to measure AAPSE.

RESULTS

Aortic annular plane systolic excursion was lower in HCM cats compared to normal cats (3.9 ± 0.9 mm versus 4.6 ± 0.9 mm, P < .001) and was lowest in HCM stage C (2.4 ± 0.6 mm, P < .001). An AAPSE <2.9 mm gave a sensitivity of 83% (95% CI 71%-91%) and specificity of 92% (95% CI 82%-97%) to differentiate HCM stage C from stage B. AAPSE correlated with mitral annular plane systolic excursion (r = .6 [.4-.7], P < .001), and atrial fractional shortening (r = .6 [.5-.7], P < .001), but showed no correlation with LV fractional shortening.

CONCLUSIONS AND CLINICAL IMPORTANCE

Aortic annular plane systolic excursion is an easily acquired echocardiographic variable and might be a new measurement of LV systolic performance in cats with HCM.

Predicting Development of Hypertrophic Cardiomyopathy and Disease Outcomes in Cats

Echocardiography is the gold standard imaging modality to diagnose hypertrophic cardiomyopathy (HCM) in cats. Echocardiographic features can predict both cats at an increased risk of developing HCM and cats with HCM at an increased risk of developing cardiovascular events or experiencing cardiac death. Left atrial dysfunction seems to be an important feature of HCM, as it is an early phenotypic abnormality and is also associated with worse outcome.

Echocardiographic assessment of right ventricular blood flow and tricuspid annular plane systolic excursion in apparently healthy domestic short-haired cats

Right ventricular parameters change in many cardiovascular diseases; so, the presence of normal right ventricular parameters is necessary to diagnose these diseases. Ten clinically healthy adult domestic short-haired cats including six males and four females in the range of 2.70 to 4.80 kg were studied using echocardiography without sedation. The speed and pressure of blood flow through the tricuspid and pulmonary valves, speed of the movement of tricuspid valve and tricuspid annular plane systolic excursion (TAPSE) were recorded using conventional pulsed-wave (PW) Doppler, tissue Doppler imaging (TDI) and M-mode, respectively. No significant statistical differences were observed between the measured values and sex, heart rate and body weight. A positive correlation was observed between the maximum velocity of the right ventricular outflow tract and heart rate and also between TAPSE slope and body weight. With determining the normal values of PW-TDI of the right ventricle in apparently healthy domestic short-haired cats, it is expected that with providing normal reference values, the diagnosis of heart diseases especially asymptomatic heart disease be achieved as soon as possible to provide the best appropriate therapeutic management and monitoring decision about them.

Echocardiographic caudal vena cava measurements in healthy cats and in cats with congestive heart failure and non-cardiac causes of cavitary effusions

BACKGROUND

Echocardiographic indices of the inferior vena cava have been associated with elevated right atrial pressures in humans.

HYPOTHESIS/OBJECTIVES

Describe caudal vena caval (CVC) sonographic dimensions in healthy cats compared to cats with cardiogenic cavitary effusion (CCE), cardiogenic pulmonary edema (CPE), or non-cardiac causes of cavitary effusion (NCE).

ANIMALS

30 healthy control cats and 52 client-owned cats with CCE, CPE, or NCE examined at two university hospitals.

METHODS

Sagittal 2-dimensional (2D) and M-mode CVC dimensions were acquired from the subxiphoid view. Caudal vena cava collapsibility index (CVC-CI) was calculated. Variables were compared between study groups using Kruskal-Wallis and Dunn's Bonferroni testing. Receiver operating characteristic curves were used to assess sensitivity and specificity for diagnostic categories.

RESULTS

Healthy cats had sagittal 2D and M-mode (median, interquartile range) CVC maximal dimensions of 2.4 mm (1.3-4.0) and 3.4 mm (1.5-4.9) and CVC-CI of 52% (45.2-61.8) and 55% (47.8-61.3), respectively. The CVC maximal dimensions in healthy controls were smaller than in cats with cavitary effusions or pulmonary edema (all P<0.05). CVC-CI was different between CCE and NCE (P<0.0001) with cutoffs of CVC-CI ≤38% (2D) or ≤29% (M-mode) being 90.5% and 85.7% sensitive, and 94.4% and 100% specific for diagnosis of CCE, respectively.

CONCLUSIONS AND CLINICAL IMPORTANCE

Caudal vena cava measurements are larger in cats with cavitary effusions and cats with CPE than healthy cats. In cats with cavitary effusion, decreased CVC-CI, ≤38% (2D) or ≤29% (M-mode), was helpful in distinguishing between cardiogenic and noncardiogenic etiology.

Thin and hypokinetic myocardial segments in cats with cardiomyopathy

INTRODUCTION/OBJECTIVES

Thin and hypokinetic myocardial segments (THyMS) represent adverse ventricular (LV) remodeling in human hypertrophic cardiomyopathy. We describe the echocardiographic features and outcome in cats with THyMS, and in a subpopulation, the echocardiographic phenotype before LV wall thinning was detected (pre-THyMS).

ANIMALS

Eighty client-owned cats.

MATERIALS AND METHODS

Retrospective multicenter study. Clinical records were searched for cats with THyMS, defined as LV segment(s) with end-diastolic wall thickness (LVWT) <3 mm and hypokinesis in the presence of ≥one LV segment(s) with LVWT >4 mm and normal wall motion. When available, echocardiograms pre-THyMS were assessed. Survival time was defined as time from first presentation with THyMS to death.

RESULTS

Mean thickest LV wall segment (MaxLVWT) was 6.1 mm (95% CI 5.8-6.4 mm) and thinnest (MinLVWT) was 1.7 mm (95% CI 1.6-1.9 mm). The LV free wall was affected in 74%, apex in 13% and septum in 5%. Most cats (85%) presented with heart failure and/or arterial thromboembolism. Median circulating troponin I concentration was 1.4 ng/mL ([range 0.07-180 ng/mL]). Prior echocardiography results were available for 13/80 cats, a mean of 2.5 years pre-THyMS. In segments subsequently undergoing thinning, initial MaxLVWT measured 6.7 mm (95% CI 5.8-7.7 mm) vs. 1.9 mm (95% CI 1.5-2.4 mm) at last echocardiogram (P<0.0001). Survival data were available for 56/80 cats, median survival time after diagnosing THyMS was 153 days (95% CI 83-223 days). Cardiac histopathology in one cat revealed that THyMS was associated with severe transmural scarring.

CONCLUSIONS

Cats with THyMS had advanced cardiomyopathy and a poor prognosis.

Behavioral and cardiovascular effects of a single dose of gabapentin or melatonin in cats: a randomized, double-blind, placebo-controlled trial

OBJECTIVES

The aim of this study was to verify whether a single oral dose of gabapentin (100 mg) or melatonin (3 mg) given 60 mins before a cardiac evaluation would reduce anxiety without interfering with heart rate (HR), systemic blood pressure (SBP), electrocardiogram (ECG) and echocardiographic indexes.

METHODS

Seventy-five client-owned healthy cats underwent two sets of cardiac assessments 60 mins apart, randomly divided into gabapentin, melatonin and placebo groups. The interval between treatment and the second ECG and SBP measurement was 60 mins, and 70 mins for echocardiography. A compliance score (CS) classified the behavior, focusing on the ease of handling.

RESULTS

Most variables did not change between the examinations. The placebo group showed more significant changes (SBP, tricuspid annular plane systolic excursion, HR during echocardiography, aortic flow velocity, S' wave from lateral mitral annulus), but they were not considered to be hemodynamically relevant. Gabapentin and melatonin significantly increased the cats' compliance without interfering with cardiac assessment. Eight cats presented with mild sedation, seven after gabapentin and one after melatonin. No major side effects were observed.

CONCLUSIONS AND RELEVANCE

Gabapentin tranquilized the cats when it was given 60 mins prior to ECG and SBP measurement, and 70 mins prior to echocardiography, without interfering with systolic echocardiographic indexes. Melatonin also decreased the CS, but without sedation in most cases. The waiting period may have relaxed the cats in the placebo group, resulting in lower SBP measurements. However, this tranquility did not last as some echocardiographic changes signaled a sympathetic predominance.

Timolol 0.5% ophthalmic solution influences cardiac function in healthy cats

OBJECTIVES

The aim of this study was to ascertain the effect of a drop of timolol 0.5% ophthalmic solution on the systolic function of the left ventricle (LV) and left atrium (LA), and to confirm if timolol helped appraisal of diastolic function by reducing heart rate (HR) and separating the transmitral outflow waves from tissue Doppler imaging (TDI).

METHODS

A total of 41 client-owned healthy cats underwent two echocardiograms 20 mins apart. The timolol group (33 cats) received a drop of timolol solution after the first examination. Standard and speckle-tracking echocardiography evaluated the LV and LA function of both groups at the two time points evaluated.

RESULTS

Timolol reduced HR (19%), and fractional shortening from LV (20.3%) and LA (16.6%). Septal S' decreased by 51% (from 7.7 to 5.2 cm/s) and lateral S' dropped by 43.1% (7.3 to 5.1 cm/s). Most longitudinal techniques did not change after timolol, including the mitral annular plane systolic excursion from the interventricular annulus, tricuspid annular plane systolic excursion, LV longitudinal strain and LV tissue motion annular displacement. The isovolumic relaxation time increased by 15.2% (from 54 to 64.6 ms), with most cats presenting this variable above the reference (>60 ms). Timolol did not support diastolic assessment, enabling evaluation in only 2/11 cats when using lateral TDI and 1/9 cats using septal TDI. Regarding side effects, miosis occurred in 18 cats (54.5%).

CONCLUSIONS AND RELEVANCE

Timolol reduced systolic function, decreasing standard echocardiographic variables. Regarding diastolic evaluation, although timolol decreased HR, it did not separate the mitral diastolic waves, as expected.

Tissue motion annular displacement to assess the left ventricular systolic function in healthy cats

The tissue motion annular displacement (TMAD) measures the longitudinal displacement of the mitral annulus during systole, using speckle-tracking echocardiography (STE). The main objective was to determine the TMAD means in healthy cats, exploring the correlations with systolic surrogates. The influence of age, body surface area (BSA), heart rate, and systemic blood pressure on the indices was also analyzed. One hundred ninety-three healthy, client-owned cats participated in this prospective, cross-sectional observational study undergoing conventional and STE. Apical four-chamber (AP4) and two-chamber (AP2) images were recorded for offline calculations. Mean TMAD values were similar to mitral annulus plane systolic excursion (MAPSE), varying between 4 to 4.8 mm depending on the annulus and image used. No significant differences between age and BSA categories were detected, except for AP4 MP%, reduced in the heavier group. TMAD variables showed moderate correlation with longitudinal strain (LSt) and MAPSE, but not with fraction shortening (FS) and ejection fraction (EF). The median time required for the offline calculation was 12.2 s for AP4 and 11.8 s for AP2. The technique showed moderate inter and intraobserver variation, proving a reliable tool for assessing left ventricular longitudinal systolic function in cats.

Detection of congestive heart failure by mitral annular displacement in cats with hypertrophic cardiomyopathy - concordance between tissue Doppler imaging-derived tissue tracking and M-mode

INTRODUCTION

The left ventricular systolic longitudinal function, traditionally measured by M-mode-derived mitral annular plane systolic excursion (MAPSE), is reduced in feline hypertrophic cardiomyopathy (HCM) and further reduced in cats with left-sided congestive heart failure (CHF). The objectives of this study were to compare longitudinal displacement measured by tissue tracking (TT-LD) and MAPSE in feline HCM and assess these methods' ability to differentiate CHF from preclinical HCM. A further objective was to provide preliminary reference intervals for TT-LD.

ANIMALS

Eighty-five client-owned cats.

METHODS

A retrospective case-control study. Anatomical M-mode was used to record MAPSE, and TT-LD was recorded by tissue tracking.

RESULTS

Reduced longitudinal displacement measured by either MAPSE or TT-LD was significantly associated with CHF in cats with HCM (p < 0.036). Receiver-operating characteristic analysis indicated that TT-LD (AUC: 92.9%-97.9%) was more sensitive and specific than MAPSE (AUC: 85.8%-89.1%) for the detection of CHF. A diagnostic cut-off of 2.89 mm for maximal TT-LD in the left ventricular septum resulted in a sensitivity and specificity of 100% and 83.3%, while a diagnostic cut-off of 2.41 mm in the left ventricular posterior wall resulted in a sensitivity of 100% and a specificity of 90%.

CONCLUSIONS

M-mode-derived mitral annular plane systolic excursion and TT-LD were strongly correlated, but not interchangeable. Longitudinal displacement measured by tissue tracking decreased more with disease severity than traditional MAPSE. Longitudinal displacement may help detect CHF in cats with HCM - with the maximal TT-LD of the left ventricular posterior wall achieving the highest AUC value.

Retrospective evaluation of the safety and tolerability of pimobendan in cats with obstructive vs nonobstructive cardiomyopathy

BACKGROUND

Pimobendan is frequently used off-label for treatments of cats with congestive heart failure (CHF). Concern exists regarding the safety of pimobendan in cats with outflow tract obstruction (OTO).

OBJECTIVES

In cats treated with pimobendan, incidence of adverse effects will not differ between cats with OTO vs cats with nonobstructive cardiomyopathy.

ANIMALS

Two-hundred sixty cats with CHF (57 with OTO, 203 with nonobstructive disease).

METHODS

Retrospective medical record review. Groups were compared using 2-sample t-tests, Wilcoxon rank-sum tests, and Fisher exact tests.

RESULTS

Compared to cats with nonobstructive cardiomyopathy, cats with OTO were younger (8.9 [interquartile range (IQR) 6.6] vs 10.8 [6.3] years, P = .0036), more likely to have a heart murmur (51/57 [90%] vs 76/203 [37.8%] cats, P < .0001), more likely to manifest CHF as pulmonary edema (53/57 [83%] vs 144/203 [70.9%] cats, P = .0004), and less likely to have pleural effusion (19/57 [33%] vs 122/203 [60.1%] cats, P = .0005). Adverse effects suspected to be related to pimobendan administration occurred in 12/260 cats (4.6%), including 11/203 cats (5.4%) with nonobstructive cardiomyopathy and 1/57 cat (2%) with OTO (P = .7). Pimobendan was discontinued due to adverse effects in 4/260 cats (1.5%), 3 with nonobstructive disease and 1 with OTO (P = 1.0). Acute adverse hemodynamic effects after pimobendan administration were not detected in any cats.

CONCLUSIONS AND CLINICAL IMPORTANCE

Pimobendan is well tolerated in cats with cardiomyopathy and CHF, regardless of the presence of OTO.

Echocardiographic assessment of right heart size and function in dogs with pulmonary valve stenosis

INTRODUCTION/OBJECTIVES

We sought to determine the prevalence and clinical significance of right heart remodeling and right ventricular (RV) dysfunction in dogs with pulmonary valve stenosis (PS). We also sought to evaluate repeatability of several measurements of severity of PS, right heart size, and RV function in dogs with PS.

ANIMALS, MATERIALS AND METHODS

Several indices of right atrial (RA) size and RV size and function were prospectively evaluated in 48 dogs with PS. Regression analysis was used to determine if indices of right heart size and function were independently associated with maximum transpulmonary pressure gradient (max PG) and adverse clinical findings (exercise intolerance, syncope, or right heart failure). Eight dogs underwent a second echocardiogram performed by the same operator to assess repeatability of the echocardiographic indices, which was quantified by coefficient of variation (CV) and repeatability coefficient.

RESULTS

Increased RA size (81%), increased RV wall thickness (83%), and decreased tricuspid annular plane systolic excursion (TAPSE [81%]) were common. Right atrial size, end-diastolic RV area, and RV wall thickness were independently associated with max PG. Decreased TAPSE was independently associated with adverse clinical findings. All indices except RA area (18.6%) and RV systolic velocity (20.7%) had CVs <15%. Repeatability coefficients are available to help distinguish a true change versus measurement variability during serially obtained exams.

CONCLUSIONS

Right heart remodeling and RV dysfunction are common in dogs with PS and are associated with echocardiographic and clinical severity. Results support the quantitative assessment of right heart size and function in dogs with PS.

Speckle tracking echocardiography in cats with preclinical hypertrophic cardiomyopathy

Background

Cats with hypertrophic cardiomyopathy (HCM) have decreased left ventricular (LV) longitudinal deformation detected by mitral annular plane systolic excursion (MAPSE) and speckle tracking echocardiography. People with preclinical HCM have decreased systolic LV longitudinal and radial strain (S) and strain rate (SR), with preserved circumferential S and SR.

Hypothesis/Objectives

Cats with preclinical HCM have decreased systolic LV deformation compared to normal cats.

Animals

Seventy‐three client‐owned cats with (n = 37) and without (n = 36) preclinical HCM.

Methods

Retrospective echocardiographic study. Left and right ventricular longitudinal S and SR, LV radial and circumferential S and SR were calculated by STE. Left ventricular mass was also calculated. Correlation between STE variables and LV hypertrophy was determined and receiver‐operating characteristic (ROC) curves were plotted for prediction of HCM.

Results

Cats with HCM had smaller absolute longitudinal S (−14.8 ± 3.3% vs −19.7 ± 2.7%, P < .001), longitudinal SR (−2.36 ± 0.62 vs −2.95 ± 0.68 second⁻¹, P < .001), radial S (46.2 ± 21.3% vs 66.7 ± 17.6%, P < .001), and radial SR (5.60 ± 2.08 vs 6.67 ± 1.8 second⁻¹, P < .001) compared to healthy controls. No difference was observed for circumferential S and SR. Cats with HCM had greater LV mass (13.2 ± 3.7 g vs 8.6 ± 2.7 g, P < .001). The ROC with the greatest area under the curve (AUC) for the identification of HCM (0.974) was plotted from a logistic regression equation combining LV mass, MAPSE at the free wall, and LV internal diameter in diastole (LVIDd).

Conclusions and clinical importance

Cats with preclinical HCM have decreased long axis and radial deformation. Decreased longitudinal deformation and decreased LVIDd are factors that would support a diagnosis of HCM.

Doppler-derived echocardiographic evidence of pulmonary hypertension in cats with left-sided congestive heart failure

INTRODUCTION

Pulmonary hypertension (PH) caused by left-sided congestive heart failure (L-CHF) is common in dogs and contributes to clinical signs and outcome. The aim of this study was to evaluate the prevalence of Doppler echocardiography-derived PH in a population of cats with L-CHF.

ANIMALS

The study involved 131 cats with L-CHF and 56 control cats.

METHODS

The study design is retrospective, observational study. Tricuspid regurgitation velocity, right atrial dimension, right ventricular (RV) dimension and function, RV wall thickness, pulmonary artery (PA) dimension, Doppler-derived systolic time intervals of PA flow, and presence of septal flattening were evaluated. Pulmonary hypertension was considered if tricuspid regurgitation velocity was >2.7 m/s.

RESULTS

Tricuspid regurgitation was present in 57/131 (44%) of cats with L-CHF and 24/56 (43%) in control cats based on color flow Doppler. Doppler-derived of PH was identified in 22/131 cats with L-CHF (17%). In 15/22 cats, PH was associated with cardiomyopathy, in 5/22 cases with congenital heart disease, and in 2/22 cases with other causes. Cats with Doppler-derived PH more often had chronic L-CHF, as opposed to acute L-CHF (p<0.05). All cats with Doppler-derived PH had subjectively-assessed right-sided heart enlargement, with larger right atrial and RV diameters (p<0.001), increased RV wall thickness (p<0.05), and higher prevalence of septal flattening (<0.001) and PA enlargement (p<0.05).

CONCLUSIONS

Pulmonary hypertension identified by Doppler echocardiography is not a common finding in cats with L-CHF. Right-sided heart enlargement, more frequently observed, may raise the suspicion of PH in cats with L-CHF.