A seminal study by Morganroth et al (1975) demonstrated a differential pattern of cardiac adaptation with prolonged exercise training; of eccentric pattern of left ventricular hypertrophy (LVH) in endurance trained athletes (ET) and concentric LVH in resistance trained athletes (RT). Specific inconsistencies related to the nature of any adaptation to RT; the value of new imaging technologies; the relative importance of scaling of cardiac data for differences in body size; the impact of training on the right ventricle (RV) and the fit of differential pattern of adaptation in athletes with Black ethnicity have driven the rationale for the studies included in this thesis. Study one employed meta-analysis techniques to critically evaluate the evidence base supporting or refuting that MH exists in elite male Caucasian ET & RT. Modern echocardiographic techniques were used to test whether a dichotomous LV and RV structural as well as global and regional functional adaptation was apparent in elite Caucasian ET & RT in studies 2 & 3. The final study (exploratory) was to characterize the athletic heart phenotype in a homogenous population of elite RT of West African origin (WRT) to provide new insight in relation to cardiac adaptation and ECG characteristics in non-Caucasian athlete groups. Allometric scaling approach was deployed to index LV and RV data for individual body variance in body size. The novel findings of this thesis; larger LV data in ET (LVMg: ET 232 (200 to 260), RT 220 (205 to 234), CT 166 (145 to 186)) but no concentric hypertrophy in RT within the meta-analysis, predominance of normal geometry in male athletes (65% of ET and 95% of RT) and the lack of concentric pattern of hypertrophy in RT in a cross-sectional study; no RV adaptation in RT athletes (RVD1mm: ET 45 ± 5 (39 to 57), RT 40 ± 5 (32 to 51) CT 39 ± 4 (31 to 45)); no LV or RV adaptation in WRT athletes; the importance of appropriate scaling of cardiac parameters; provide a useful re-evaluation of concepts and models in the athletic heart literature. The findings have important implications for cardiovascular screening of athletes.

Bedömningen av höger kammares systoliska funktion kan med fördel göras med ekokardiografi, bl.a. med tekniker som tvådimensionell ekokardiografi, motion-mode (M-mode) och Tissue Doppler Imaging (TDI). Mätvärden som kan fås ut av dessa tekniker är Tricuspid Annular Plane Systolic Excursion (TAPSE) och s`. TAPSE beskriver annulus tricuspidalis longitudinella rörlighet. s´ beskriver den maximala systoliska hastigheten i annulus tricuspidalis. Syftet med examensarbetet var att undersöka sambandet mellan TAPSE och s´ vid högerkammarfunktionsbestämning. Studien är en retrospektiv tvärsnittsstudie och består av 99 deltagare i åldrarna 18–90 år. Både friska och hjärt-och kärlsjuka deltagare inkluderades, men inte patienter med förmaksflimmer eller individer som var yngre än 18 år. Deltagarna undersöktes med transthorakal ekokardiografi (TTE) vid Länssjukhuset Ryhov i Jönköping, vid undersökningen mättes TAPSE och s´. Det var samma biomedicinska analytiker (BMA) som utförde undersökningarna. McNemars test utfördes och ett Kappa-värde räknades ut. Resultatet visade signifikant skillnad och Kappa-värdet var lågt vilket talar för dåligt samband mellan de båda variablerna. Utfallet i studien visar att fler deltagare klassas med normal högerkammarfunktion mätt med TAPSE, medan samma individer klassas med högerkammardysfunktion mätt med s´. Orsaken till det dåliga sambandet mellan parametrarna är okänt och bör studeras vidare i kommande studier. / The assessment of right ventricular systolic function is done by echocardiography, with techniques as twodimensional echocardiography, motion-mode (M-mode) and Tissue Doppler Imaging (TDI). Measurements ​​obtained from these techniques are Tricuspid Annular Plane Systolic Excursion (TAPSE) and s`. TAPSE describes the longitudinal movement of annulus tricuspidalis. s´ describes annulus tricuspidalis maximal systolic velocity. The purpose of this essay was to explore the relationship between TAPSE and s´. The study consists of 99 participants between the ages of 18 and 90. The population was consisted of individuals with or without cardiovascular disease, but not individuals with atrial fibrillation. Participants were investigated with transthorakal echocardiography (TTE) at Länssjukhuset Ryhov in Jönköping. At the examination both TAPSE and s´ was measured. McNemar's test was performed and a Kappa value was calculated. The result showed a significant difference and the Kappa value was low which indicates a low relationship between the variables. The outcome of the study shows that several participants are classified with normal right ventricular function measured with TAPSE, but the same individuals are classified with right ventricular dysfunction measured by s'. The reason for the poor relationship between the parameters is unknown and should be studied further in future studies.

A ecocardiografia com Doppler tecidual (EDT) e suas derivadas, o Strain Rate (StR) e o Strain (St), têm por finalidade mensurar a velocidade e a deformação miocárdicas, avaliando assim as funções sistólica e diastólica do miocárdio. Devido à grande semelhança entre a distrofia muscular de Duchenne (DMD), que acomete o homem e se caracteriza por contínua degeneração, necrose e fibrose de tecidos musculares esquelético e cardíaco e apresenta caráter recessivo ligada ao cromossomo X, e a distrofia muscular canina (DMC), considerada geneticamente análoga à DMD, alguns modelos experimentais com cães da raça Golden Retriever têm sido desenvolvidos com a finalidade de auxiliar os estudos relacionados com as referidas enfermidades. No presente estudo, 24 cães da raça Golden Retriever, divididos em três grupos denominados controle, portadores e afetados foram avaliados por meio da ecocardiografia convencional bem como por Doppler tecidual, Strain Rate e Strain com o objetivo de avaliar os índices das funções sistólica e diastólica de cães com distrofia muscular, a fim de aprimorar o diagnóstico e, conseqüentemente, o tratamento dos casos de DMD, assim como os de cães com DMC. Observaram-se diferenças entre alguns parâmetros das funções sistólica e diastólica, principalmente entre o grupo controle e o grupo dos animais afetados, sendo então possível afirmar que cães da raça Golden Retriever, afetados pela DMC e sem manifestações clínicas de insuficiência cardíaca congestiva (ICC), apresentam alterações dos índices tanto da função sistólica como da função diastólica, passíveis de serem detectadas pela EDT, St e StR. / Tissue Doppler imaging (TDI), strain rate, and strain allow for recording myocardial velocity and deformity, for assessment of systolic and diastolic function. There is great similarity between Duchennes muscular dystrophy (DMD) that affects humans, characterized by continuous degeneration, necrosis and fibrosis of skeletal and cardiac muscle and is recessive, linked to X-chromosome, and canine muscular dystrophy (CMD), which is considered genetically analogous to the DMD. Some experimental models have been developed in order to study these diseases. In this study, 24 Golden retriever dogs, allocated to 3 different groups (control, bearer and affected) were evaluated by conventional echo and TDI, strain rate (StR) and strain (St) aiming to evaluate systolic and diastolic function indices of dystrophic dogs in order to improve diagnosis and treatment of DMD cases, as well as CMD. Differences were observed in some variables of systolic and diastolic function specially between control and affected groups. It was possible to confirm that Golden Retriever dogs, affected by CMD and without clinical signs of congestive heart failure, present changes in systolic and diastolic indices, detected by TDI, StR and St.

A cardiomiopatia hipertrófica (CMH) é a principal cardiopatia dos felinos e é caracterizada por hipertrofia miocárdica concêntrica, sem dilatação ventricular. Disfunções miocárdicas ocorrem em gatos com CMH, mas pouco se conhece a respeito destas alterações nos estágios iniciais da afecção. Em gatos da raça Maine Coon, a mutação no gene MyBPC-A31P está relacionada com a CMH de origem familial, porém, a correlação exata entre o genótipo e o fenótipo ainda é inconclusiva. A ecocardiografia tecidual é uma modalidade não invasiva que permite avaliação da função miocárdica e é mais sensível que a ecocardiografia convencional. Para avaliar a função sistólica e diastólica, antes ou após a ocorrência de hipertrofia ventricular, gatos da raça Maine Coon (n=57), geneticamente testados para a mutação, foram avaliados por meio de ecocardiografia convencional e tecidual (nas modalidades Doppler tecidual pulsado, Doppler tecidual colorido e strain). Posteriormente, foram fenotipicamente classificados em: normais (n=45), suspeitos (n=7) e acometidos pela CMH (n=5); e genotipicamente classificados em: negativos (n=28), heterozigotos (n=26) e homozigotos para a mutação (n=3). Valores de velocidades miocárdicas (Doppler tecidual pulsado e colorido) e valores de strain, medidos na região basal e média do septo interventricular (SIV), da parede livre do ventrículo esquerdo (PVE), da parede anterior do ventrículo esquerdo (PAVE), da parede posterior do ventrículo esquerdo (PPVE) e do segmento radial da PVE, foram comparados nos diferentes grupos. Observou-se que as velocidades longitudinais Em (Doppler tecidual pulsado) na região média da PVE foram menores nos gatos com CMH quando comparados com suspeitos e normais. Os valores de Em/Am (Doppler tecidual colorido), na região basal do SIV, foram inferiores nos gatos com CMH quando comparados com suspeitos e normais. A relação E/Em (Doppler tecidual colorido), na região basal do SIV, foi maior nos gatos com CMH em relação aos suspeitos e normais. E os valores de Sm (Doppler tecidual colorido), em região basal da PVE, foram menores nos gatos heterozigotos em relação aos negativos, ambos sem hipertrofia ventricular. Observou-se correlação positiva entre a ocorrência de fusão das ondas Em e Am e a frequência cardíaca; e correlação positiva entre valores de Sm e Em e a frequência cardíaca (Doppler tecidual pulsado e colorido). Enquanto à ecocardiografia convencional observou-se um estado de contratilidade aparentemente normal, os valores de strain (em região média do SIV) nos gatos com CMH foram inferiores aos dos gatos normais. Valores de strain (em região basal da PAVE) também foram menores nos gatos heterozigotos em relação aos negativos, antes mesmo da hipertrofia ventricular. Observou-se correlação negativa entre valores de strain e espessura miocárdica. A ecocardiografia tecidual é uma nova modalidade ecocardiográfica reprodutível em gatos que, isoladamente, não permite a identificação de gatos com mutação antes do desenvolvimento de hipertrofia. O strain possibilita a detecção de anormalidades sistólicas em gatos da raça Maine Coon, apesar da aparente normalidade à ecocardiografia convencional. Apesar da expectativa em relação ao uso da ecocardiografia tecidual para a identificação precoce de indivíduos portadores da CMH, ainda há necessidade de estudos mais extensos e com maior número de indivíduos. / Hypertrophic cardiomyopathy (HCM) is the most common feline heart disease and is characterized by increased cardiac mass with a hypertrophied nondilated left ventricle. Myocardial dysfunction occurs in cats with HCM but less is known about dysfunctions in initial stages of HCM. A mutation in MYBPC-A31P gene has been identified in a colony of Maine Coon cats with HCM. However, the close correlation between genotype and phenotype still be inconclusive. Myocardial analysis by tissue Doppler imaging (TDI) is a noninvasive echocardiographic method to assess systolic and diastolic function that is more sensitive than conventional echocardiography. To evaluate diastolic and systolic function in cats with mutation, with or without ventricular hypertrophy, Maine Coon cats (n=57) were screened for mutation and examined with both echocardiography and TDI (pulsed tissue Doppler, color tissue Doppler and Strain methods). Then, were phenotypically classified in: normal (n=45), suspects (n=7) and HCM group (n=5); and genotypically classified in: negative (n=28), heterozygous (n=26) and homozygous group (n=3). Myocardial velocities (by pulsed and color tissue Doppler imaging) and peak myocardial strain, measured in the basal and mildventricular segment of the interventricular septal wall (IVS), left ventricular free wall (LVW), left ventricular anterior wall (LVAW), left ventricular posterior wall (LVPW) and radial segment of LVW, was compared among different groups. A decreased longitudinal Em velocities (pulsed tissue Doppler) at the mildventricular segment of LVW was observed in HCM cats compared with suspects and normal cats. A decreased longitudinal Em/Am (color tissue Doppler) at the basal segment of IVS was observed in HCM cats compared with suspects and normal cats. A significant increased longitudinal E/Em (color tissue Doppler) at the basal segment of IVS was observed in HCM cats compared with suspects and normal cats. And a significant decreased longitudinal Sm (color tissue Doppler) at the basal segment of the LVW was observed in heterozygous cats compared with negative cats, both without hypertrophy. There was a positive correlation between summated early and late diastolic velocities (EmAm) and heart rate; and a positive correlation between Sm and Em velocities and heart rate, both in pulsed and in color TDI. Whereas conventional echocardiography demonstrated an apparently normal contractile state, myocardial strain (at mildventricular segment of IVS) in HCM cats was decreased compared with normal group. Myocardial strain (at basal segment of LVAW) also was decreased in heterozygous cats compared with negative group; and was decreased in heterozygous cats compared with negative group, both without ventricular hypertrophy. And there was a negative correlation between strain values and wall thickness. TDI analyses are a new, valuable and reproducible method in cats that alone is not able to identify cats with mutation before myocardial hypertrophy. Strain method allows noninvasive detection of abnormal systolic deformation in Maine Coons cats with HCM mutation despite apparently normal left ventricular systolic function. Despite high expectations regarding the use of TDI for early identification of individuals with HCM, there is still need for larger studies with greater numbers of individuals.

<p>Kvantifisering av hjertets muskelfunksjon med tøyning og tøyningshastighet målt med ultralyd for vurdering av koronar sykdom.</p><p>Automatisert metode versus manuell ved akutt hjerteinfarkt og ultralyd stress test.</p><p>Vanligvis måles hjertets muskelfunksjon med ultralyd, en mye brukt metode for å diagnostisere hjertesykdommer. Vurderingen av muskelfunksjonen baserer seg i dag på en subjektiv visuell gradering av bevegelsen av hjertemuskelen, og dette krever erfaring. En ny automatisert diagnostisk ultralydsmetode basert på måling av hastigheten i hjertemuskelen gir et kvantitativt mål på muskelens tøyning og sammentrekning. Den nye metoden gir ny og mer detaljert informasjon om hjertets funksjon og om pasientens prognose enn vanlig ultralydsvurdering.</p><p>Den nye metoden er mer presis ved oppfølgning etter hjerteinfarkt. Et hjerteinfarkt gir nedsatt bevegelse av muskelen og måles med den nye metoden som nedsatt hastighet som muskelen forkortes med. Små forandringer i den skadde hjertemuskelen, ikke alltid synlige for øyet, kan mer nøyaktig følges over tid med den nye metoden. Utbredelsen av hjerteinfarktet kan også vurderes mer nøyaktig.</p><p>Det samme gjelder når angina vurderes under belastning. Når en pasient ikke kan sykle eller gå på tredemølle brukes en medisinsk belastningstest. Ved å belaste hjertet med et medikament som øker hjertemuskelens arbeid samtidig med en ultralydundersøkelse, kan vi oppdage redusert blodforsyningsreserve i hjertet. Stresstesten hjelper til med å vurdere om en trang blodåre bør åpnes etter et hjerteinfarkt, og til å vurdere pasienters risiko for hjertekomplikasjoner før en større operasjon. Den nye metoden gir i tillegg mer informasjon om den langsiktige prognosen sammenlignet med den gamle metoden. Vi har funnet at den nye ultralydsmetoden er mer presis (gir større diagnostisk treffsikkerhet i diagnostikk av koronarsykdom) sammenlignet med den gamle.</p><p>Måling av sammentrekningshastigheter i hjertemuskelen ble utviklet og testet på Institutt for sirkulasjon og bildediagnostikk ved NTNU av Andreas Heimdal og Asbjørn Støylen i 1998. Metoden trengte teknisk videreutvikling og testing i et større pasientmateriale. Metoden har ikke fått stor utbredelse på sykehusene pga støyfylte kurver og tidskrevende analyser, men med denne automatiserte metoden blir brukervennligheten større som muliggjør klinisk bruk.</p> / Paper I and II preprinted with kind permission of Elsevier, sciencedirect.com

Kvantifisering av hjertets muskelfunksjon med tøyning og tøyningshastighet målt med ultralyd for vurdering av koronar sykdom. Automatisert metode versus manuell ved akutt hjerteinfarkt og ultralyd stress test. Vanligvis måles hjertets muskelfunksjon med ultralyd, en mye brukt metode for å diagnostisere hjertesykdommer. Vurderingen av muskelfunksjonen baserer seg i dag på en subjektiv visuell gradering av bevegelsen av hjertemuskelen, og dette krever erfaring. En ny automatisert diagnostisk ultralydsmetode basert på måling av hastigheten i hjertemuskelen gir et kvantitativt mål på muskelens tøyning og sammentrekning. Den nye metoden gir ny og mer detaljert informasjon om hjertets funksjon og om pasientens prognose enn vanlig ultralydsvurdering. Den nye metoden er mer presis ved oppfølgning etter hjerteinfarkt. Et hjerteinfarkt gir nedsatt bevegelse av muskelen og måles med den nye metoden som nedsatt hastighet som muskelen forkortes med. Små forandringer i den skadde hjertemuskelen, ikke alltid synlige for øyet, kan mer nøyaktig følges over tid med den nye metoden. Utbredelsen av hjerteinfarktet kan også vurderes mer nøyaktig. Det samme gjelder når angina vurderes under belastning. Når en pasient ikke kan sykle eller gå på tredemølle brukes en medisinsk belastningstest. Ved å belaste hjertet med et medikament som øker hjertemuskelens arbeid samtidig med en ultralydundersøkelse, kan vi oppdage redusert blodforsyningsreserve i hjertet. Stresstesten hjelper til med å vurdere om en trang blodåre bør åpnes etter et hjerteinfarkt, og til å vurdere pasienters risiko for hjertekomplikasjoner før en større operasjon. Den nye metoden gir i tillegg mer informasjon om den langsiktige prognosen sammenlignet med den gamle metoden. Vi har funnet at den nye ultralydsmetoden er mer presis (gir større diagnostisk treffsikkerhet i diagnostikk av koronarsykdom) sammenlignet med den gamle. Måling av sammentrekningshastigheter i hjertemuskelen ble utviklet og testet på Institutt for sirkulasjon og bildediagnostikk ved NTNU av Andreas Heimdal og Asbjørn Støylen i 1998. Metoden trengte teknisk videreutvikling og testing i et større pasientmateriale. Metoden har ikke fått stor utbredelse på sykehusene pga støyfylte kurver og tidskrevende analyser, men med denne automatiserte metoden blir brukervennligheten større som muliggjør klinisk bruk. / Paper I and II preprinted with kind permission of Elsevier, sciencedirect.com

There is a large need for accurate methods detecting cardiovascular diseases, since they are one of the leading causes of mortality in the world, accounting for 29.3% of all deaths. Due to the complexity of the cardiovascular system, it is very challenging to develop methods for quantification of its function in order to diagnose, prevent and treat cardiovascular diseases. Ultrasound is a technique allowing for inexpensive, noninvasive imaging, but requires an experienced echocardiographer. Nowadays, methods like Tissue Doppler imaging (TDI) and Speckle tracking imaging (STI), measuring motion and deformation in the myocardium and the vessel walls, are getting more common in routine clinical practice, but without a proper visualization of the data provided by these methods, they are time-consuming and difficult to interpret. Thus, the general aim of this thesis was to develop novel ultrasound-based methods for accurate quantification and easily interpretable visualization of cardiovascular function. Five methods based on TDI and STI were developed in the present studies. The first study comprised development of a method for generation of bull’s-eye plots providing a color-coded two-dimensional visualization of myocardial longitudinal velocities. The second study proposed the state diagram of the heart as a new circular visualization tool for cardiac mechanics, including segmental color-coding of cardiac time intervals. The third study included development of a method describing the rotation pattern of the left ventricle by calculating rotation axes at different levels of the left ventricle throughout the cardiac cycle. In the fourth study, deformation data from the artery wall were tested as input to wave intensity analysis providing information of the ventricular – arterial interaction. The fifth study included an in-silico feasibility study to test the assessment of both radial and longitudinal strain in a kinematic model of the carotid artery. The studies showed promising results indicating that the methods have potential for the detection of different cardiovascular diseases and are feasible for use in the clinical setting. However, further development of the methods and both quantitative comparison of user dependency, accuracy and ease of use with other established methods evaluating cardiovascular function, as well as additional testing of the clinical potential in larger study populations, are needed. / QC 20100727

Pain and disorders of the human skeletal muscles are one of the most common reasons for medical consultations in the western countries today and there is a great need to improve both the understanding and treatment of several different muscular conditions. Techniques describing the muscle function in vivo are often limited by either their invasiveness or lack of spatial resolution. Electromyography (EMG) is the most common approach to assess the skeletal muscle function in vivo, providing information on the neurological input. However, the spatial resolution is in general limited and there are difficulties reaching deep musculature without using invasive needles. Moreover, it does not provide any information about muscle structure or mechanical aspects. Quantitative ultrasound techniques have gained interest in the area of skeletal muscles and enables non-invasive and in-vivo insight to the intramuscular activity, through the mechanical response of the activation. However, these techniques are developed and evaluated for cardiovascular applications and there are important considerations to be made when applying these methods in the musculoskeletal field.  This thesis is based on the work from four papers with the main focus to investigate and describe some of these considerations in combination with the development of processing and analyzing methods that can be used to describe the physiological characteristics of active muscle tissue. In the first paper the accuracy of the Doppler based technique Tissue Velocity Imaging (TVI) was evaluated in a phantom study for very low tissue velocities and the effect of the pulse repetition frequency was considered. The second paper presents a biomechanical model to describe the TVI strain’s dependency on the muscle fiber pennation angle. In the third and fourth papers the intramuscular activity pattern was assessed through the regional tissue deformation by motion mode (M-mode) strain imaging. The activity patterns were analyzed during force regulation and for the effects of fatigue. The work of this thesis show promising results for the application of these methods on skeletal muscles and indicate high clinical potential where quantitative ultrasound may be a valuable tool to reach a more multifaceted and comprehensive insight in the musculoskeletal function. However, the methodological considerations are highly important for the optimized application and further evaluation and development of analyzing strategies are needed. / <p>QC 20130516</p>

Sub-endocardial fibres line the inner surface of both ventricles and are responsible for longitudinal oscillations of the mitral annulus, such oscillations may be measured using tissue Doppler echocardiography (IDE). During systole the annulus descends and during early diastole (ETDE) and atrial systole (ATDE) itascends. This thesis examined whether changes in the velocity of the annulus ineach of these phases of oscillation, measured using tissue Dopplerechocardiography (TDE), could determine the nature of increases in left ventricular size (pathological or physiological). Study one examined differences at rest in longitudinal velocities between individuals with hypertrophic cardiomyopathy (HCM), hypertension (HT), weightlifters, runners and controls, (n = 15 all groups) and all groups were aged between 20 - 36 years. The results demonstrated that both pathological groups had systolic and ETDE velocities significantly lower than groups with physiological hypertrophy (weightlifters or runners) or controls p < 0.05. AIDE however was not significantly different between groups. Additionally runners also demonstrated a significantly higher ETDE than either weightlifters or controls (p < 0.05). Binomial logistic regression identified longitudinal systolic velocity < 9 cm s" 1 and ETDE velocity < 11 cm s" 1 as the best combination of variables to predict pathological increases in heart size. Study two examined older subjects in order to determine whether the criteria set out in study one were applicable to senior athletes. The subject groups were the same as in study one however all subjects were aged between 36-55. In this case systolic annular velocity was significantly lower in groups with pathological LVH but ETDE < 9 cm s" 1 was a better differentiator. Binomial logistic regression identified ETDE < 9 cm s" 1 and a mitral E / A ratio < 1 as the best combination of variables to predict pathological LVH. Study three examined the age related changes in long axis function using the pooled data from studies one and two. This demonstrated that in the pathological LVH groups only ETDE / ATDE ratio was significantly correlated with age (r = - 0.5 p < 0.05) suggesting that there appears to be no summation of the effects of pathology and age on mitral annular velocities. The control groups demonstrated a significant age related reduction in all long axis variables (systolic velocity r = - 0.7 p < 0.05; ETDE r = - 0.6 p < 0.01; ATDE r = 0.5 p < 0.05; ETD E / ATDE r = - 0.5 p< 0.01). Weightlifters however did not demonstrate an age related decline in either systolic or diastolic annular velocities. Runners had no age related decline in systolic annular velocities, and whilst they had an age dependent fall in ETDE ( r = - 0.62 p < 0.05) the older runners ETDE were still significantly faster (p < 0.05) than that seen in control subjects. Study four investigated relationship between mitral annular velocity and VOiruK in runners, weightlifters and controls. These results demonstrated peak exercise E TDE strongly correlated to VO^PEAK (r = 0.8 p < 0.01). ConclusionsTaken together these data suggest that longitudinal velocities of the mitral annulus may be useful in determining the nature of increases in heart size, in addition the increased performance of endurance - trained athletes is due in part to functional changes of the long axis.

A cardiomiopatia hipertrófica (CMH) é a principal cardiopatia dos felinos e é caracterizada por hipertrofia miocárdica concêntrica, sem dilatação ventricular. Disfunções miocárdicas ocorrem em gatos com CMH, mas pouco se conhece a respeito destas alterações nos estágios iniciais da afecção. Em gatos da raça Maine Coon, a mutação no gene MyBPC-A31P está relacionada com a CMH de origem familial, porém, a correlação exata entre o genótipo e o fenótipo ainda é inconclusiva. A ecocardiografia tecidual é uma modalidade não invasiva que permite avaliação da função miocárdica e é mais sensível que a ecocardiografia convencional. Para avaliar a função sistólica e diastólica, antes ou após a ocorrência de hipertrofia ventricular, gatos da raça Maine Coon (n=57), geneticamente testados para a mutação, foram avaliados por meio de ecocardiografia convencional e tecidual (nas modalidades Doppler tecidual pulsado, Doppler tecidual colorido e strain). Posteriormente, foram fenotipicamente classificados em: normais (n=45), suspeitos (n=7) e acometidos pela CMH (n=5); e genotipicamente classificados em: negativos (n=28), heterozigotos (n=26) e homozigotos para a mutação (n=3). Valores de velocidades miocárdicas (Doppler tecidual pulsado e colorido) e valores de strain, medidos na região basal e média do septo interventricular (SIV), da parede livre do ventrículo esquerdo (PVE), da parede anterior do ventrículo esquerdo (PAVE), da parede posterior do ventrículo esquerdo (PPVE) e do segmento radial da PVE, foram comparados nos diferentes grupos. Observou-se que as velocidades longitudinais Em (Doppler tecidual pulsado) na região média da PVE foram menores nos gatos com CMH quando comparados com suspeitos e normais. Os valores de Em/Am (Doppler tecidual colorido), na região basal do SIV, foram inferiores nos gatos com CMH quando comparados com suspeitos e normais. A relação E/Em (Doppler tecidual colorido), na região basal do SIV, foi maior nos gatos com CMH em relação aos suspeitos e normais. E os valores de Sm (Doppler tecidual colorido), em região basal da PVE, foram menores nos gatos heterozigotos em relação aos negativos, ambos sem hipertrofia ventricular. Observou-se correlação positiva entre a ocorrência de fusão das ondas Em e Am e a frequência cardíaca; e correlação positiva entre valores de Sm e Em e a frequência cardíaca (Doppler tecidual pulsado e colorido). Enquanto à ecocardiografia convencional observou-se um estado de contratilidade aparentemente normal, os valores de strain (em região média do SIV) nos gatos com CMH foram inferiores aos dos gatos normais. Valores de strain (em região basal da PAVE) também foram menores nos gatos heterozigotos em relação aos negativos, antes mesmo da hipertrofia ventricular. Observou-se correlação negativa entre valores de strain e espessura miocárdica. A ecocardiografia tecidual é uma nova modalidade ecocardiográfica reprodutível em gatos que, isoladamente, não permite a identificação de gatos com mutação antes do desenvolvimento de hipertrofia. O strain possibilita a detecção de anormalidades sistólicas em gatos da raça Maine Coon, apesar da aparente normalidade à ecocardiografia convencional. Apesar da expectativa em relação ao uso da ecocardiografia tecidual para a identificação precoce de indivíduos portadores da CMH, ainda há necessidade de estudos mais extensos e com maior número de indivíduos. / Hypertrophic cardiomyopathy (HCM) is the most common feline heart disease and is characterized by increased cardiac mass with a hypertrophied nondilated left ventricle. Myocardial dysfunction occurs in cats with HCM but less is known about dysfunctions in initial stages of HCM. A mutation in MYBPC-A31P gene has been identified in a colony of Maine Coon cats with HCM. However, the close correlation between genotype and phenotype still be inconclusive. Myocardial analysis by tissue Doppler imaging (TDI) is a noninvasive echocardiographic method to assess systolic and diastolic function that is more sensitive than conventional echocardiography. To evaluate diastolic and systolic function in cats with mutation, with or without ventricular hypertrophy, Maine Coon cats (n=57) were screened for mutation and examined with both echocardiography and TDI (pulsed tissue Doppler, color tissue Doppler and Strain methods). Then, were phenotypically classified in: normal (n=45), suspects (n=7) and HCM group (n=5); and genotypically classified in: negative (n=28), heterozygous (n=26) and homozygous group (n=3). Myocardial velocities (by pulsed and color tissue Doppler imaging) and peak myocardial strain, measured in the basal and mildventricular segment of the interventricular septal wall (IVS), left ventricular free wall (LVW), left ventricular anterior wall (LVAW), left ventricular posterior wall (LVPW) and radial segment of LVW, was compared among different groups. A decreased longitudinal Em velocities (pulsed tissue Doppler) at the mildventricular segment of LVW was observed in HCM cats compared with suspects and normal cats. A decreased longitudinal Em/Am (color tissue Doppler) at the basal segment of IVS was observed in HCM cats compared with suspects and normal cats. A significant increased longitudinal E/Em (color tissue Doppler) at the basal segment of IVS was observed in HCM cats compared with suspects and normal cats. And a significant decreased longitudinal Sm (color tissue Doppler) at the basal segment of the LVW was observed in heterozygous cats compared with negative cats, both without hypertrophy. There was a positive correlation between summated early and late diastolic velocities (EmAm) and heart rate; and a positive correlation between Sm and Em velocities and heart rate, both in pulsed and in color TDI. Whereas conventional echocardiography demonstrated an apparently normal contractile state, myocardial strain (at mildventricular segment of IVS) in HCM cats was decreased compared with normal group. Myocardial strain (at basal segment of LVAW) also was decreased in heterozygous cats compared with negative group; and was decreased in heterozygous cats compared with negative group, both without ventricular hypertrophy. And there was a negative correlation between strain values and wall thickness. TDI analyses are a new, valuable and reproducible method in cats that alone is not able to identify cats with mutation before myocardial hypertrophy. Strain method allows noninvasive detection of abnormal systolic deformation in Maine Coons cats with HCM mutation despite apparently normal left ventricular systolic function. Despite high expectations regarding the use of TDI for early identification of individuals with HCM, there is still need for larger studies with greater numbers of individuals.