Anomalous coronary artery causing transmural ischaemia and ventricular tachycardia in a high school athlete.

A previously asymptomatic 15-year-old boy was treated at our institution after an episode of chest pain, palpitation, and syncope while playing in a high school soccer game. The patient's resting electrocardiogram was normal. A transthoracic echocardiogram showed an anomalous left main coronary artery originating from the right sinus of Valsalva. Contrast-enhanced multidetector computed tomography demonstrated clearly that the anomalous vessel coursed between the aorta and the pulmonary trunk (interarterial subtype). Treadmill testing registered several nonsustained polymorphic ventricular tachycardias and transmural myocardial ischaemia in the early recovery phase (ST-elevation up to 5mm in CM5 and V2 leads). The patient underwent bypass grafting. One year later, he remains asymptomatic, and new treadmill tests have been normal. In this patient, severe transmural myocardial ischaemia was detected, possibly due to collapse or vasospasm of the anomalous vessel, triggering life-threatening ventricular arrhythmias.

Myocardial fibrosis detected by cardiac CT predicts ventricular fibrillation/ventricular tachycardia events in patients with hypertrophic cardiomyopathy.

BACKGROUND: Myocardial fibrosis (MF) occurs in up to 80% of subjects with asymptomatic or mildly symptomatic hypertrophic cardiomyopathy (HCM) and can constitute an arrhythmogenic substrate for re-entrant, life-threatening ventricular arrhythmias in predisposed persons. OBJECTIVE: The aim was to investigate whether MF detected by delayed enhancement cardiac CT is predictive of ventricular tachycardia (VT) and fibrillation (VF) that require appropriate therapy by an implantable cardioverter defibrillator (ICD) in patients with HCM. METHODS: Twenty-six patients with HCM with previously (for at least 1 year) implanted ICD underwent MF evaluation by cardiac CT. MF was quantified by myocardial delayed enhanced cardiac CT. Data on ICD firing were recorded every 3 months after ICD implantation. Risk factors for sudden cardiac death in patients with HCM were evaluated in all patients. RESULTS: MF was present in 25 of 26 patients (96%) with mean fibrosis mass of 20.5 ± 15.8 g. Patients with appropriate ICD shocks for VF/VT had significantly greater MF mass than patients without (29.10 ± 19.13 g vs 13.57 ± 8.31 g; P = .01). For a MF mass of at least 18 g, sensitivity and specificity for appropriate ICD firing were 73% (95% CI, 49%-88%) and 71% (95% CI, 56%-81%), respectively. Kaplan-Meier curves indicated a significantly greater VF/VT event rate in patients with MF mass ≥18 g than in patients with MF <18 g (P = .02). In the Cox regression analysis, the amount of MF was independently associated with VF/VT in ICD-stored electrograms. CONCLUSION: The mass of MF detected by cardiac CT in patients with HCM at high risk of sudden death was associated with appropriate ICD firings.

Diltiazem as an alternative to beta-blocker in coronary artery computed tomography angiography.

BACKGROUND: Reducing heart rate (HR) in CT angiography of the coronary arteries (CTACor) is critical to image quality. The effectiveness of calcium channel blockers as alternatives for patients with contraindications to beta-blockers has not been established. OBJECTIVES: To compare the efficacy in the reduction of HR and RR variability of metoprolol and diltiazem in CTACor. METHODS: Prospective, randomized, open study that included patients with clinical indication of CTACor in sinus rhythm with HR > 70 bpm and no use of agents that could interfere with HR. Fifty patients were randomized to the groups: metoprolol IV 5-15 mg or up to HR ≤ 60 bpm (M), and diltiazem IV 0.25 to 0.60 mg/kg or up to HR ≤ 60 bpm (D). Blood pressure (BP) and HR were measured at baseline, 1 minute, 3 minutes and 5 minutes after the agents, at the acquisition and after CTACor. RESULTS: HR reduction in absolute values was higher in group M than in group D (1, 3, 5 min, acquisition and post-test). The percentage reduction of HR was significantly higher in group M only 1 min and 3 min after the start of the agents. There was no difference in 5 min at acquisition and after examination. The percentage RR variability in group D was lower than that in group M during acquisition (RR variability/mean HR of acquisition). A single case of AVB, 2:1 Mobitz I occurred, which was spontaneously reverted (group D). CONCLUSION: We conclude that diltiazem is an effective and safe alternative to beta-blockers in the reduction of HR when performing computed tomography angiography of coronary arteries.

An unusual association of endomyocardial fibrosis and hypertrophic cardiomyopathy in a patient with heart failure.

A 69-year-old female patient presented heart failure with preserved ejection fraction and atrial fibrillation. Echocardiography and late gadolinium enhancement magnetic resonance imaging were suggestive of endomyocardial fibrosis (EMF). The patient underwent cardiac surgery, and after surgery, she developed low cardiac output syndrome and died. Postmortem examination revealed residual fibrosis of the left ventricle (LV), mild endocardial fibrous deposition of the right ventricle, and severe concentric, symmetrical LV hypertrophy. Histological examination of the surgically resected material from the LV confirmed EMF. Histopathology of the interventricular septum disclosed myocardial hypertrophy and disarray plus fine interstitial fibrosis, typical of hypertrophic cardiomyopathy. The present case illustrates the association of two different patterns of cardiomyopathies in the same patient.

[Myocardial fibrosis in patients with hypertrophic cardiomyopathy and high risk for sudden death]. / Fibrose miocárdica em pacientes com cardiomiopatia hipertrófica com alto risco para morte súbita cardíaca.

BACKGROUND: The stratification of risk for sudden death in hypertrophic cardiomyopathy (HCM) continues to be a true challenge due to the great heterogeneity of this disease's presentation, as most individuals remain asymptomatic during their entire lives and others present sudden death as first symptom. Recent studies have suggested that myocardial fibrosis may represent an important substrate for the malignant ventricular arrhythmias, that are responsible for the cases of sudden death related to this disease. OBJECTIVE: To assess the prevalence and quantification of myocardial fibrosis (MF) in hypertrophic cardiomyopathy (HCM) patients with implantablecardioverter - defibrillator (ICD) indicated due to their high risk or recovered from cardiac sudden death. METHODS: Twenty-eight HCM patients with ICD were submitted to multidetector computed tomography to assess myocardial fibrosis by delayed enhancement technique. RESULTS: Myocardial fibrosis was present in 96% of these HCM patients with (20.38 +/- 15.55 g) comprising 15.96 +/- 10.20% of the total myocardial mass. MF was observed in a significantly higher prevalence as compared to other classical risk factors for sudden death. CONCLUSION: It is possible to conclude that there is a high prevalence of myocardial fibrosis in hypertrophic cardiomyopathy patients with high-risk or recovered from cardiac sudden death, like those with clinical indication to implantable cardioverter -defibrillator. The higher prevalence of myocardial fibrosis in comparison to classical risk factors of worse prognosis raise the hypothesis that the myocardial fibrosis may be an important substrate in the genesis of lifethreatening arrhythmias in these high risk HCM population.

Diltiazem como alternativa ao betabloqueador na angiotomografia de artérias coronárias / Diltiazem as an alternative to beta-blocker in coronary artery computed tomography angiography

FUNDAMENTO: A redução da frequência cardíaca (FC) na angiografia por tomografia das artérias coronarianas (ATCCor) é fundamental para a qualidade de imagem. A eficácia dos bloqueadores de cálcio como alternativas para pacientes com contraindicações aos betabloqueadores não foi definida. OBJETIVOS: Comparar a eficácia na redução da FC e variabilidade RR do metoprolol e diltiazem na ATCCor. MÉTODOS: Estudo prospectivo, randomizado, aberto, incluiu pacientes com indicação clínica de ATCCor, em ritmo sinusal, com FC>70bpm e sem uso de agentes que interferissem com a FC. Cinquenta pacientes foram randomizados para grupos: metoprolol IV 5-15 mg ou até FC≤60 bpm(M), e diltiazem IV 0,25-0,60mg/kg ou até FC≤60 bpm (D). Pressão arterial (PA) e FC foram aferidas na condição basal, 1min, 3min e 5min após agentes, na aquisição e após ATCCor. RESULTADOS: A redução da FC em valores absolutos foi maior no grupo M que no grupo D (1, 3, 5min, aquisição e pós-exame). A redução percentual da FC foi significativamente maior no grupo M apenas no 1 min e 3 min após início dos agentes. Não houve diferença no 5 min, durante a aquisição e após exame. A variabilidade RR percentual do grupo D foi estatisticamente menor do que a do grupo M durante a aquisição (variabilidade RR/ FC média da aquisição). Um único caso de BAV, 2:1 Mobitz I, revertido espontaneamente ocorreu (grupo D). CONCLUSÃO: Concluímos que o diltiazem é uma alternativa eficaz e segura aos betabloqueadores na redução da FC na realização de angiografia por tomografia computadorizada das artérias coronarianas. (Arq Bras Cardiol. 2012; [online].ahead print, PP.0-0).

BACKGROUND: Reducing heart rate (HR) in CT angiography of the coronary arteries (CTACor) is critical to image quality. The effectiveness of calcium channel blockers as alternatives for patients with contraindications to beta-blockers has not been established. OBJECTIVES: To compare the efficacy in the reduction of HR and RR variability of metoprolol and diltiazem in CTACor. METHODS: Prospective, randomized, open study that included patients with clinical indication of CTACor in sinus rhythm with HR > 70 bpm and no use of agents that could interfere with HR. Fifty patients were randomized to the groups: metoprolol IV 5-15 mg or up to HR ≤ 60 bpm (M), and diltiazem IV 0.25 to 0.60 mg/kg or up to HR ≤ 60 bpm (D). Blood pressure (BP) and HR were measured at baseline, 1 minute, 3 minutes and 5 minutes after the agents, at the acquisition and after CTACor. RESULTS: HR reduction in absolute values was higher in group M than in group D (1, 3, 5 min, acquisition and post-test). The percentage reduction of HR was significantly higher in group M only 1 min and 3 min after the start of the agents. There was no difference in 5 min at acquisition and after examination. The percentage RR variability in group D was lower than that in group M during acquisition (RR variability/mean HR of acquisition). A single case of AVB, 2:1 Mobitz I occurred, which was spontaneously reverted (group D). CONCLUSION: We conclude that diltiazem is an effective and safe alternative to beta-blockers in the reduction of HR when performing computed tomography angiography of coronary arteries. (Arq Bras Cardiol. 2012; [online].ahead print, PP.0-0).

Left ventricular free-wall rupture after acute myocardial infarction imaged by cardiovascular magnetic resonance.

This manuscript describes a rare situation where after acute myocardial infarction a patient underwent cardiovascular magnetic resonance (CMR), which identified a previously undiagnosed rupture of the free wall of the LV, leading to successful surgical management.

The emerging role of MRI in the diagnosis and management of cardiomyopathies.

Cardiac magnetic resonance (CMR) has emerged as an important tool for the evaluation of cardiomyopathies, providing highly accurate information on the macroscopic changes of cardiac morphology, function, and tissue composition. For myocardial tissue characterization, the technique of myocardial delayed enhancement is a potentially promising tool for diagnosis, management, and prognosis. Several CMR approaches are now available to better diagnose and prognosticate dilated cardiomyopathy, hypertrophic cardiomyopathy, restrictive cardiomyopathy, arrhythmogenic right ventricular disease, myocarditis, and other cardiomyopathies.

Fibrose miocárdica em pacientes com cardiomiopatia hipertrófica com alto risco para morte súbita cardíaca / Myocardial fibrosis in patients with hypertrophic cardiomyopathy and high risk for sudden death

FUNDAMENTO: A estratificação de risco para morte súbita na cardiomiopatia hipertrófica (CMH), continua a ser um verdadeiro desafio devido à grande heterogeneidade da sua apresentação, em que a maioria dos indivíduos permanecem assintomáticos por toda sua vida e outros apresentam a morte súbita como primeiro sintoma. Recentes trabalhos vêm sugerindo que a fibrose miocárdica pode constituir-se em um importante substrato para as arritmias ventriculares malignas, responsáveis pela morte súbita nesta doença. OBJETIVO: Avaliação da prevalência e quantificação da fibrose miocárdica (FM), em pacientes com CMH com alto risco ou recuperados de morte súbita, portadores de cardiodesfibrilador implantável (CDI). MÉTODOS: Vinte e oito pacientes com CMH portadores de CDI foram submetidos à tomografia computadorizada com múltiplos detectores, para realização da técnica de realce tardio, e avaliação da fibrose miocárdica. RESULTADOS: 96 por cento dos pacientes apresentavam fibrose miocárdica (20,38 ± 15,55 gramas) correspondendo a 15,96 ± 10,20 por cento da massa miocárdica total. A FM foi significativamente mais prevalente que os demais fatores de risco clássicos para morte súbita. CONCLUSÃO: Concluímos que existe uma alta prevalência de fibrose miocárdica em pacientes com cardiomiopatia hipertrófica de alto risco ou recuperados de morte súbita, como neste grupo - portadores de cardiodesfibrilador implantável. A maior prevalência da fibrose miocárdica comparada aos fatores de risco de pior prognóstico levantam a hipótese de que a fibrose miocárdica possa ser um importante substrato potencialmente necessário na gênese das arritmias desencadeadoras da morte súbita.

BACKGROUND: The stratification of risk for sudden death in hypertrophic cardiomyopathy (HCM) continues to be a true challenge due to the great heterogeneity of this disease's presentation, as most individuals remain asymptomatic during their entire lives and others present sudden death as first symptom. Recent studies have suggested that myocardial fibrosis may represent an important substrate for the malignant ventricular arrhythmias, that are responsible for the cases of sudden death related to this disease. OBJECTIVE: To assess the prevalence and quantification of myocardial fibrosis (MF) in hypertrophic cardiomyopathy (HCM) patients with implantablecardioverter - defibrillator (ICD) indicated due to their high risk or recovered from cardiac sudden death. METHODS: Twenty-eight HCM patients with ICD were submitted to multidetector computed tomography to assess myocardial fibrosis by delayed enhancement technique. RESULTS: Myocardial fibrosis was present in 96 percent of these HCM patients with (20.38 ± 15.55 g) comprising 15.96 ± 10.20 percent of the total myocardial mass. MF was observed in a significantly higher prevalence as compared to other classical risk factors for sudden death. CONCLUSION: It is possible to conclude that there is a high prevalence of myocardial fibrosis in hypertrophic cardiomyopathy patients with high-risk or recovered from cardiac sudden death, like those with clinical indication to implantable cardioverter -defibrillator. The higher prevalence of myocardial fibrosis in comparison to classical risk factors of worse prognosis raise the hypothesis that the myocardial fibrosis may be an important substrate in the genesis of lifethreatening arrhythmias in these high risk HCM population.

Ressonância magnética cardiovascular e tomografia computadorizada cardiovascular nas doenças não-coronárias / Role of cardiovascular magnetic resonance and computed tomography in noncoronary diseases

A tomografia computadorizada e, principalmente, a ressonância magnética cardiovascular têm se mostrado de utilidade cada vez maior para a avaliação de doenças cardiovasculares não-isquêmicas. A alta resolução tanto espacial como temporal desses métodos possibilita a aquisição de imagens com grande detalhamento anatômico, permitindo a avaliação da relação espacial entre estruturas adjacentes de forma não-invasiva. A tomografia tem particular importância para a análise vascular e é o melhor método para detecção de calcificações. No entanto, tem a desvantagem de utilizar contraste iodado e radiação ionizante, de não apresentar alta resolução de contraste entre as estruturas, e de adquirir imagens predominantemente estáticas. A ressonância magnética, por sua vez, é um método que não utiliza radiação ionizante e, por meio de diversas sequências de pulsos e técnicas de aquisição de imagens, é capaz de fornecer, além do detalhamento anatômico...

Diagnóstico de progressão de doença coronária em pacientes previamente tratados com stents pela tomografia computadorizada de múltiplos detectores / Diagnosis of the progression of coronary artery disease in patients previously treated by stents using multislice computed tomography

INTRODUÇÃO: Pacientes previamente submetidos a intervenção coronária percutânea podem apresentar progressão de doença aterosclerótica ao longo do tempo, com o desenvolvimento de novas lesões em outros locais da árvore arterial coronária, o que pode representar um desafio diagnóstico. O objetivo deste trabalho foi avaliar a eficácia da tomografia computadorizada por múltiplos detectores na detecção da progressão de doença arterial coronária. MÉTODO: Entre julho de 2007 e julho de 2008, foram avaliados 60 pacientes previamente submetidos a implante de stents coronários e que apresentassem quadro clínico suspeito de recorrência de isquemia miocárdica tardia. Os pacientes foram divididos em dois grupos: grupo I (GI), 30 pacientes avaliados pela tomografia computadorizada por múltiplos detectores; e grupo II (GII), 30 casos avaliados com cintilografia miocárdica. Todos os pacientes foram posteriormente submetidos a cinecoronariografia. RESULTADOS: Os dados demográficos, a artéria tratada e o número de stents por paciente não diferiam entre os grupos. A tomografia computadorizada por múltiplos detectores identificou progressão de doença em 9 (30%) pacientes e reestenose em 2 (6,7%); a cintilografia miocárdica identificou 8 (26,7%) casos de progressão de doença e 3 (10%) de reestenose. A cinecoronariografia identificou 10 casos de progressão de doença no GI (3 com estenoses entre 55% e 60%) e 12 no GII (4 com obstruções entre 50% e 60%) e confirmou todas as suspeitas de reestenose. CONCLUSÃO: A tomografia computadorizada por múltiplos detectores demonstrou, em nossa casuística, bom desempenho na identificação da progressão de doença aterosclerótica em pacientes previamente tratados com stents. Caso trabalhos adicionais, com maior número de pacientes, confirmem estes achados, a tomografia computadorizada por múltiplos detectores poderá incorporar mais essa indicação a seu espectro diagnóstico.

BACKGROUND: Patients undergoing percutaneous coronary intervention may present progression of coronary artery disease in the late follow-up, leading to the development of new lesions in different sites of the coronary arteries, which may represent a diagnostic challenge. The goal of this paper was to evaluate the contribution of multislice computed tomography in this setting. METHOD: From July 2007 to July 2008 we analyzed 60 patients with suspect late myocardial ischemia after coronary stent implantation. Patients were divided in two groups. In Group I, 30 patients were evaluated by multislice computed tomography and in Group II, 30 patients were evaluated by myocardial scintigraphy. All patients were subsequently submitted to coronary angiography. RESULTS: Demographic data, the treated vessel and the mean number of stents per patient were not significantly different in both groups. Multislice computed tomography identified progression of coronary disease in 9 patients (30%) and restenosis in 2 (6.7%); myocardial scintigraphy identified 8 cases (26.7%) of disease progression and 3 cases (10%) of restenosis. Coronary angiography revealed 10 cases of disease progression (3 cases with obstructions between 55% and 60%) in Group I and 12 in Group II (4 patients with obstructions between 50% and 60%) and confirmed all suspected restenosis. CONCLUSION: Multislice computed tomography proved to be sensitive to detect progression of coronary artery disease in patients previously treated with stent implantation. Should larger scale studies confirm such findings this method could have an important role in the clinical evaluation of these patients.

Associação entre a densidade radiológica da placa à tomografia de coronárias com 64 colunas de detectores e a composição da placa ao ultrassom intravascular com técnica de histologia virtual: resultados de uma comparação pareada prospectiva / Association between plaque radiological density by 64-slice multidetector computed tomography and plaque composition by intravascular ultrasound virtual histology: results from a prospective matched comparison

INTRODUÇÃO: Pouco se conhece sobre a comparação entre métodos de avaliação da placa aterosclerótica coronária, como a tomografia computadorizada com múltiplos detectores (TCMD) e o ultrassom intravascular com técnica de histologia virtual (HV). MÉTODO: Foram analisados prospectivamente os vasos coronários principais de 21 pacientes à TCMD e à HV. Cada vaso analisado foi dividido em subsegmentos de 4 mm (unidades básicas para a análise). Os subsegmentos foram pareados conforme sua localização axial. Os limites da luz e do vaso foram traçados à HV e à TCMD com o auxílio de programas específicos. A contribuição porcentual de cada componente da placa à HV e a razão necrose:cálcio foram quantificadas. A placa à TCMD foi avaliada por sua densidade radiológica em unidades Hounsfield (UH). RESULTADOS: Foram analisados 641 subsegmentos, obtidos de 70 vasos. A contribuição porcentual dos componentes à HV foi: fibroso = 64%; fibrolipídico = 20%; núcleo necrótico = 11%; cálcio denso = 5%; e razão necrose:cálcio = 5,1. A atenuação da placa à TCMD variou de 44 UH a 440 UH. Para a análise, as placas foram divididas em três grupos de tamanhos semelhantes, conforme a densidade da placa à TCMD (1º tercil: 44-128 UH, 2º tercil: 129-178 UH, e 3º tercil: 178-440 UH). Houve correlação inversa entre a razão necrose/cálcio à HV e densidade da placa à TCMD (1º tercil: 4,1, 2º tercil: 2,9, e 3º tercil: 2,3; P < 0,01) e relação direta entre o porcentual de cálcio denso à HV e a densidade da placa à TCMD (1º tercil: 1,5%, 2º tercil: 2,5%, e 3º tercil: 3,8%; P < 0,01). CONCLUSÃO: A densidade da placa aterosclerótica avaliada pela TCMD em tomógrafo de 64 colunas de detectores associa-se significativamente com a composição da placa à HV.

BACKGROUND: Little is known about the comparative results of coronary plaque assessment by multidetector computed tomography (MDCT) against the novel intravascular ultrasound virtual histology (IVUS-VH). METHOD: Threevessel IVUS-VH and MDCT were prospectively obtained from 21 patients. Each vessel was divided into 4-mm subsegments, which were used as the basic unit for analysis. The 4-mm subsegments were matched by their axial location. Lumen and outer vessel boundaries for IVUS-VH and for MDCT were traced by specific automatic softwares. The percent contribution of each IVUS-VH plaque tissue type and the ratio of necrotic tissue to calcium were quantified. The MDCT plaque was evaluated through its average density in Hounsfield units (HU). RESULTS: A total of 641 matched subsegments were computed from 70 vessels. Overall, the average IVUS-VH tissue composition was: fibrous = 64%; fibrofatty = 20%; necrotic tissue = 11%; dense calcium = 5%; and calcium/necrosis ratio = 5.1. MDCT average plaque attenuation ranged from 44 to 440 HU and was divided into three groups of similar size (1st tertile: 44-128 HU; 2nd tertile: 129-178 HU; 3rd tertile: 178-440 HU). There was an inverse correlation between IVUS-VH necrotic/ dense calcium ratio and MDCT plaque density (1st tertile: 4.1, 2nd tertile: 2.9, 3rd tertile: 2.3; P < 0.01) and a direct relationship between percent IVUS-VH dense calcium and MDCT plaque density (1st tertile: 1.5%, 2nd tertile: 2.5%, 3rd tertile: 3.8%; P < 0.01). CONCLUSION: Atherosclerotic plaque density evaluated by 64-MDCT significantly associates with plaque composition assessed by IVUS-VH.