RESUMO
OBJECTIVES: The study was done to define the role of the autonomic nervous system in postoperative tetralogy of Fallot. BACKGROUND: Subsequent to surgical correction of tetralogy of Fallot, patients are at long-term risk of sudden death owing to ventricular electrical instability. The status of the sympathetic nervous system in these patients, known to play an important role in other patients at risk, remains unknown. METHODS: We used (123)I metaiodobenzylguanidine (MIBG) with tomographic imaging, combined with assessment of heart rate variability (HRV), to evaluate the activity of the sympathetic nervous system. We analyzed 22 patients who had undergone total correction of tetralogy of Fallot: 13 with either no or minor ventricular arrhythmias, and 9 with sustained ventricular tachycardia or ventricular fibrillation. RESULTS: Analysis of HRV revealed a reduction in vagal control and sympathetic dominance in all patients compared with a healthy control group of 20 subjects. A significant difference was found in the standard deviation of all the adjacent intervals between normal beats (SDNN) in patients with or without severe ventricular arrhythmias. A significant reduction in uptake of (123)I MIBG was demonstrated 30 min after IV injection, and a trend toward reduction after 5 h, associated with reduced washout indices. These data reflect a decrease in the number of nerve endings in the right and left ventricular walls, and an inhomogeneous distribution of the adrenergic nervous system. The uptake of MIBG was significantly reduced in the patients at risk of ventricular tachycardia or fibrillation. CONCLUSIONS: Subsequent to surgical correction of tetralogy of Fallot, the positive correlation between myocardial uptake of MIBG, SDNN and the QRS dispersion confirmed the usefulness of analysis of the adrenergic nervous system to stratify patients at risk of life-threatening arrhythmias.
Assuntos
Fibras Adrenérgicas/fisiologia , Doenças do Sistema Nervoso Autônomo/fisiopatologia , Complicações Pós-Operatórias/fisiopatologia , Taquicardia Ventricular/fisiopatologia , Tetralogia de Fallot/cirurgia , Adolescente , Adulto , Doenças do Sistema Nervoso Autônomo/mortalidade , Criança , Pré-Escolar , Morte Súbita Cardíaca/epidemiologia , Morte Súbita Cardíaca/etiologia , Ecocardiografia Doppler em Cores , Eletrocardiografia Ambulatorial , Feminino , Frequência Cardíaca/fisiologia , Humanos , Lactente , Masculino , Complicações Pós-Operatórias/mortalidade , Prognóstico , Fatores de Risco , Sistema Nervoso Simpático/fisiopatologia , Taquicardia Ventricular/mortalidade , Tetralogia de Fallot/mortalidade , Tetralogia de Fallot/fisiopatologia , Tomografia Computadorizada de Emissão de Fóton Único , Fibrilação Ventricular/mortalidade , Fibrilação Ventricular/fisiopatologiaAssuntos
Transplante de Coração , Paraproteinemias/epidemiologia , Fatores Etários , Análise de Variância , Ciclosporina/administração & dosagem , Feminino , Seguimentos , Rejeição de Enxerto/imunologia , Transplante de Coração/imunologia , Humanos , Imunossupressores/administração & dosagem , Incidência , Masculino , Pessoa de Meia-Idade , Paraproteinemias/imunologia , Estudos Retrospectivos , Fatores de Risco , Fatores de TempoAssuntos
Cardiomiopatias/cirurgia , Transplante de Coração , Miopatias Mitocondriais/complicações , Distrofias Musculares/complicações , Adulto , Cardiomiopatias/complicações , Cardiomiopatias/metabolismo , Desmina/metabolismo , Distrofina/metabolismo , Feminino , Seguimentos , Humanos , Masculino , Miopatias Mitocondriais/metabolismo , Distrofias Musculares/metabolismoRESUMO
BACKGROUND: Management of cyclosporine (CsA)-associated hyperuricemia in heart transplantation (HT) is difficult. Because of the myelotoxicity of combined allopurinol and azathioprine, we tested sulfinpyrazone. METHODS: We studied 120 HT recipients (109 men; mean age at HT, 52+/-10 years). All had received allopurinol for at least 6 months, which was stopped for 1 month before initiation of sulfinpyrazone. Mean follow-up from HT to onset of sulfinpyrazone (200 mg/day) was 59+/-41 months. We stopped the drug after 6+/-2 months. We compared CsA level and daily dose, serum creatinine, blood urea, and uric acid at onset and before interruption of sulfinpyrazone and, as control, in the last 6 months of allopurinol. RESULTS: Mean uricemia decreased with allopurinol (0.58+/-0.12 vs. 0.41+/-0.07 mmol/liter, p = 0.0001) as well as with sulfinpyrazone (0.51+/-0.13 vs. 0.40+/-0.12 mmol/liter, p = 0.0001). Mean creatinine increased (171+/-42 and 164+/-35 micromol/liter, p = 0.01) with allopurinol, whereas it tended to decrease with sulfinpyrazone (160+/-35 and 154+/-48 micromol/liter, p = NS). Mean urea did not change with allopurinol (14+/-5 vs. 15+/-7 mmol/liter, p = NS), but fell with sulfinpyrazone (14.01+/-5 vs. 12.60 +/-5 mmol/liter, p = 0.0004). Mean CsA levels were constant with allopurinol (193+/-73 vs. 188+/-65 ng/ml, p = NS), although CsA dose was slightly reduced (2.7+/-0.8 vs. 2.6+/-0.8 mg/kg/day, p = 0.007). Conversely, CsA levels dropped with sulfinpyrazone (183+/-89 vs. 121 +/-63 ng/ml, p = 0.0001) despite an increase in CsA daily dose (2.6 +/-0.9 vs. 2.8+/-0.9 mg/kg/day, p = 0.0001). Two subjects were treated for acute rejection. We observed no other side effects. In HT recipients sulfinpyrazone, as an alternative to allopurinol, is effective in achieving metabolic control of hyperuricemia. However, this drug reduced CsA levels, thus the risk of rejection is present.
Assuntos
Ciclosporina/antagonistas & inibidores , Transplante de Coração , Imunossupressores/antagonistas & inibidores , Sulfimpirazona/farmacologia , Uricosúricos/farmacologia , Alopurinol/efeitos adversos , Alopurinol/uso terapêutico , Creatinina/sangue , Ciclosporina/efeitos adversos , Ciclosporina/sangue , Interações Medicamentosas , Feminino , Seguimentos , Rejeição de Enxerto/terapia , Humanos , Imunossupressores/efeitos adversos , Imunossupressores/sangue , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Ureia/sangue , Ácido Úrico/sangueRESUMO
We evaluated the utility of positron emission tomography in differentiating patients with idiopathic dilated cardiomyopathy from those with ischemic cardiomyopathy. Twenty consecutive non-diabetic patients with dilatation (end-diastolic volume > or = 120 cc/m2) and reduced systolic function (ejection fraction < or = 40%) of the left ventricle on cineangiography, underwent coronary angiography, F18 fluorodeoxyglucose (F18-FDG) (glucose load technique) and N13-ammonia (N13-NH3) positron emission tomography. A semiquantitative score based on the extension and the severity of the uptake defects was calculated. Endomyocardial biopsy was performed in patients with normal coronary arteries. Ten patients (group A) had normal coronary arteries and histologic features of the endomyocardium fitting with the diagnosis of idiopathic dilated cardiomyopathy. Cineangiography showed critical stenosis of at least one major coronary artery in the other 10 patients (group B). The two groups were similar in age. left ventricular end-diastolic volume and ejection fraction. Both N13-NH3, positron emission tomography and F18-FDG positron emission tomography scores were lower in group A than in group B: 0.1 +/- 0.3 vs. 10.6 +/- 5.1 (P<0.0001) and 2.4 +/- 4.4 vs. 9.9 +/- 4.1 (P<0.0001) respectively. but only N13-NH3 positron emission tomography allowed a complete separation of the two groups (score range 0-1 group A vs. 4-12 group B). The F18-FDG score value showed some overlapping between the two groups (score range 0-12 in the group A vs. 2-17 in the group B). All three idiopathic dilated cardiomyopathy patients with a F18-FDG score value >2 had left bundle branch block on standard ECG. Positron emission tomography imaging with N13-NH3 and F18-FDG provided a complete differentiation between idiopathic dilated cardiomyopathy and ischemic cardiomyopathy patients. However patients with left bundle branch block on ECG could present defects in FDG uptake even if affected by idiopathic dilated cardiomyopathy.
Assuntos
Cardiomiopatia Dilatada/diagnóstico por imagem , Doença das Coronárias/diagnóstico por imagem , Tomografia Computadorizada de Emissão/métodos , Adulto , Idoso , Amônia , Cardiomiopatia Dilatada/etiologia , Circulação Coronária , Doença das Coronárias/complicações , Diagnóstico Diferencial , Feminino , Fluordesoxiglucose F18 , Humanos , Masculino , Pessoa de Meia-Idade , Isótopos de Nitrogênio , Compostos Radiofarmacêuticos , Sensibilidade e EspecificidadeRESUMO
Effective arterial elastance (Ea) is the coupling parameter between the left ventricle and peripheral circulation in normal subjects. If left ventricular end systolic pressure (Pes), contractility (Es) and Ea are known, left ventricular end diastolic volume (LVEDV) and ejection fraction of the ventricle are completely determined. The aim of this study was to give an analytical expression for Ea in patients with mitral and aortic regurgitation, and predict both LVEDV and the effect of vasodilator therapy on LVEDV. Twenty-three subjects with atypical chest pain, 15 patients with mitral insufficiency and 11 with aortic insufficiency underwent diagnostic cardiac catheterization, coronary angiography, and left ventricular cineangiography, which was analyzed quantitatively. Ea was 2.05 +/- 0.63 in normal subjects, while it was 1.28 +/- 0.71 and 1.57 +/- 0.87 in patients with mitral and aortic insufficiency, respectively. All these groups differed with ANOVA test (p = 0.0031). We tested the ability of the analytical expressions for Ea in normal subjects, and patients with mitral insufficiency or aortic insufficiency to predict measured Ea and LVEDV. Ea and LVEDV were predicted rather accurately in every case (p < 0.0001). We used published data to test the effect of resistance modulation on LVEDV. Predicted and measured LVEDV were linearly correlated both in aortic (p < 0.0001) and mitral insufficiency (p = 0.027). Moreover, in some cases a left ventricular enlargement after vasodilator therapy could be anticipated because of an unbalanced decrease in resistance and heart rate. Ea seems to be the coupling parameter between the left ventricle and the peripheral circulation not only in normal subjects, but also in patients with mitral or aortic regurgitation; its measurement before administering vasodilating drugs may be useful in order to predict the effects on LVEDV, and achieve an optimal ventriculoarterial coupling.
Assuntos
Insuficiência da Valva Aórtica/fisiopatologia , Insuficiência da Valva Mitral/fisiopatologia , Contração Miocárdica , Função Ventricular Esquerda , Insuficiência da Valva Aórtica/tratamento farmacológico , Complacência (Medida de Distensibilidade) , Diástole , Frequência Cardíaca , Humanos , Insuficiência da Valva Mitral/tratamento farmacológico , Volume Sistólico , Resistência Vascular , Vasodilatadores/uso terapêutico , Pressão VentricularRESUMO
BACKGROUND AND AIM OF THE STUDY: Although the transvalvular gradient is described as flow-dependent, pressure-dependence of the gradient, irrespective of flow, has not been demonstrated. METHODS: The Sheffield pulse duplicator equipped with a X-Cell 21 porcine valve mounted in the aortic position was used. Transaortic gradient was measured at a constant rate of 80 beats/min, while flow was kept at 2, 5 or 8 l/min, and systemic pressure was increased up to 200 mmHg by adjusting peripheral resistance manually. Valve area was computed with the Gorlin formula. A total of 87 measurements was carried out. RESULTS: For each flow, transvalvular gradient increased linearly with pressure, and computed area decreased. The slope of the pressure-gradient relationship was independent of flow. CONCLUSION: Transaortic gradient depends not only on flow, but also shows pressure-dependency that should be taken into account when evaluating aortic stenosis, especially in hypertensive and hypotensive states.
Assuntos
Valva Aórtica/fisiologia , Circulação Coronária , Modelos Cardiovasculares , Fluxo Pulsátil , Resistência Vascular , Estenose da Valva Aórtica/fisiopatologia , Circulação Coronária/fisiologia , HumanosRESUMO
OBJECTIVE: To validate the accuracy of the prognostic significance of non-invasive clinical diagnostic indices as predictors of sustained ventricular tachycardia (sVT) or fibrillation (VF) in patients undergoing repair for tetralogy of Fallot. METHODS: One way analysis of variance and pairwise comparison of the values with the Bonferroni correction, logistic multivariate analysis, and ordinal logistic analysis were used to study quantitative electrocardiographic and echocardiographic variables in 66 patients who had undergone surgery for tetralogy of Fallot by ventriculotomy at a mean (SD) age of 11.8 (9.5) years. The mean (SD) period of follow up was 16.1 (5.7) years after surgery. RESULTS: Four groups of patients were identified by ECG and 24 hour Holter monitoring: 19 (28.7%) without ventricular arrhythmias, 34 (51.5%) with minor ventricular arrhythmias, seven (10.6%) with non-sustained ventricular tachycardia (nsVT), and six (9.0%) with sVT or VF. One way analysis indicated significant differences in QT dispersion (QTd) and end diastolic volume of the right ventricle (EDVRV) among the groups. Univariate logistic analysis showed EDVRV, QTd, and QRS duration to be significantly associated with sVT or VF. Stepwise multivariate analysis and ordinal logistic analysis showed QTd to be preferable to QRS duration as an indicator, because it was unrelated to EDVRV, and was capable of separating different probability curves for nsVT as opposed to sVT or VF. CONCLUSIONS: Stratification of patients undergoing corrective surgery for tetralogy of Fallot and at risk of life threatening arrhythmias is possible by simple and inexpensive means, which provide sensitive and specific indices.
Assuntos
Complicações Pós-Operatórias , Taquicardia Ventricular/etiologia , Tetralogia de Fallot/cirurgia , Fibrilação Ventricular/etiologia , Adolescente , Adulto , Criança , Pré-Escolar , Morte Súbita Cardíaca/etiologia , Ecocardiografia Doppler , Eletrocardiografia , Feminino , Seguimentos , Humanos , Modelos Logísticos , Masculino , Cuidados Pós-Operatórios/métodos , Complicações Pós-Operatórias/diagnóstico , Prognóstico , Curva ROC , Análise de Regressão , Taquicardia Ventricular/diagnóstico , Fibrilação Ventricular/diagnósticoRESUMO
Mutations in the sarcoglycan genes cause autosomal-recessive muscular dystrophies. Because sarcoglycan genes and their protein products are highly expressed both in skeletal and cardiac muscle, patients with these mutations might be expected to be at risk to develop dilated cardiomyopathy. We therefore studied 13 patients with alpha-, beta-, gamma-sarcoglycan gene mutations by thorough cardiological assessment. Electrocardiographic or echocardiographic abnormalities were observed in about 30% of cases showing a severe course of muscular dystrophy. No correlation was found between the presence of cardiac abnormalities and the type of mutation or sarcoglycan gene involved. The cardiac involvement was never severe, but it may be detected in early stages of the muscle disease. The absence of overt cardiac dysfunction may be due to lower sarcoglycan protein expression in cardiac than skeletal muscle or to less sarcolemmal instability at the myocardial level, possibly related to the different distribution of forces generated by contraction of the myocardium with respect to proximal limb-girdle muscles.
Assuntos
Proteínas do Citoesqueleto/genética , Coração/fisiologia , Glicoproteínas de Membrana/genética , Distrofias Musculares/genética , Adolescente , Adulto , Western Blotting , Criança , Pré-Escolar , Feminino , Genes Recessivos , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Mutação , FenótipoRESUMO
Adjusted-dose warfarin is effective for stroke prevention in patients with nonrheumatic atrial fibrillation (AF), but the risk of bleeding is high, especially among the elderly. Fixed minidose warfarin is effective in preventing venous thromboembolism with low risk of bleeding and no need for frequent clinical monitoring. Patients > 60 years with nonrheumatic AF were randomized in an open-labeled trial to receive fixed minidose warfarin (1.25 mg/day) or standard adjusted-dose warfarin (International Normalized Ratio [INR] between 2.0 and 3.0). Primary outcome events were ischemic stroke, peripheral or visceral embolism, cerebral or fatal bleeding, and vascular death. Secondary end points were major bleeding, myocardial infarction, and death. This study was discontinued before completion in light of publication of the Stroke Prevention in Atrial Fibrillation III trial, which indicated that low-intensity fixed-dose warfarin treatment (i.e., INR < 1.5) was insufficient for stroke prevention in high-risk patients with nonrheumatic AF. From a total of 1,209 considered patients, 303 were randomized to be studied (150 in the minidose group and 153 in the adjusted-dose group). Mean follow-up was 14.5 months. The rate of cumulative primary events was 11.1% (95% confidence intervals [CI] 4.0 to 18.2) in the fixed minidose group and 6.1% (95% CI 1.1 to 11.1) in the adjusted-dose group (p = 0.29). The rate of ischemic stroke was significantly higher in the minidose group (3.7% vs 0% per year, p = 0.025). Major bleedings were more frequent in standard treatment group (2.6% vs 1% per year, p = 0.19). Most thromboembolic complications occurred at INRs < 1.2, whereas the majority of hemorrhages occurred at INRs > 3.0. No significant difference in primary outcome events was observed in the abbreviated study. However, the significantly increased occurrence of ischemic stroke in the fixed minidose warfarin group suggests that this regimen does not protect patients with nonrheumatic AF.
Assuntos
Anticoagulantes/administração & dosagem , Fibrilação Atrial/tratamento farmacológico , Embolia e Trombose Intracraniana/prevenção & controle , Varfarina/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Fibrilação Atrial/complicações , Intervalo Livre de Doença , Feminino , Humanos , Coeficiente Internacional Normatizado , Embolia e Trombose Intracraniana/etiologia , Masculino , Pessoa de Meia-Idade , Resultado do TratamentoRESUMO
Sustained inotropic stimulation, such as dobutamine infusion, has the potential to cause an additional contractile deterioration in viable but chronically hypoperfused and dysfunctioning myocardium, by inducing ischemia. Postextrasystolic potentiation (PESP) represents a potent inotropic stimulus without risk of provoking ischemia, as it is instantaneous. In this study, we assessed the role of PESP-echocardiographic examination in predicting the recovery of regional contractility after coronary revascularization. We examined 105 consecutive patients with multivessel coronary artery disease who were candidates for bypass surgery; 79 were included in this prospective study. Preoperative reversibility of contractile dysfunction in asynergic myocardial regions was determined by PESP, with a coupling interval of 500 msec decreasing to 300 msec, with a progressive decrease by 10 msec. The examination was accompanied by continuous 2-dimensional (2D) echocardiographic monitoring. The assessed sensitivity and specificity were 92% and 87%, respectively; the predictive accuracy was 90%. These results demonstrated that PESP echocardiography is a useful and cost-effective method for identifying viable myocardium in patients undergoing myocardial revascularization.
Assuntos
Doença das Coronárias/cirurgia , Ecocardiografia Doppler/métodos , Revascularização Miocárdica , Disfunção Ventricular/diagnóstico por imagem , Adulto , Idoso , Doença das Coronárias/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Prognóstico , Estudos Prospectivos , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Insulin-dependent diabetes mellitus (IDDM) is associated with an increased incidence of heart failure due to several factors, and in some cases a specific cardiomyopathy has been suggested. OBJECTIVES: This study sought to assess the mechanisms of exercise-induced left ventricular (LV) dysfunction in asymptomatic patients with IDDM in the absence of hypertensive or coronary artery disease. METHODS: Fourteen consecutive patients with IDDM were enrolled (10 men, 4 women; mean [+/- SD] age 28.5 +/- 6 years); 10 healthy subjects matched for gender (7 men, 3 women) and age (28.5 +/- 3 years) constituted the control group. LV volume, LV ejection fraction (LVEF) and end-systolic wall stress were calculated by two-dimensional echocardiography at rest and during isometric exercise. LV contractile reserve was assessed by post-extrasystolic potentiation (PESP) obtained by transesophageal cardiac electrical stimulation and dobutamine infusion. Myocardial iodine-123 metaiodobenzylguanidine (MIBG) scintigraphy was performed to assess adrenergic cardiac innervation. RESULTS: Diabetic patients were classified into group A (n = 7), with an abnormal LVEF response to handgrip (42 +/- 7%), and group B (n = 7), with a normal response (72 +/- 8%). Baseline LVEF was normal in both group A and B patients (60 +/- 6% vs. 61 +/- 7%, p = NS). In group A patients, the LV circumferential wall stress-LVEF relation showed an impairment in LVEF disproportionate to the level of LV afterload. No significant changes in LVEF occurred during dobutamine (60 +/- 6% vs. 64 +/- 10%, p = NS), whereas PESP significantly increased LVEF (60 +/- 6% vs. 74 +/- 6%, p < 0.001); PESP at peak handgrip normalized the abnormal LVEF (42 +/- 7% vs. 72 +/- 5%, p < 0.001); and MIBG uptake normalized for body weight or for LV mass was lower than that in normal subjects (1.69 +/- 0.30 vs. 2.98 +/- 0.82 cpm/MBq per g, p = 0.01) and group B diabetic patients (vs. 2.79 +/- 0.94 cpm/MBq per g, p = 0.01). Finally, a strong linear correlation between LVEF at peak handgrip and myocardial MIBG uptake normalized for LV mass was demonstrated in the study patients. CONCLUSIONS: Despite normal contractile reserve, a defective blunted recruitment of myocardial contractility plays an important role in determining exercise LV dysfunction in the early phase of diabetic cardiomyopathy. This abnormal response to exercise is strongly related to an impairment of cardiac sympathetic innervation.
Assuntos
Fibras Adrenérgicas/fisiologia , Diabetes Mellitus Tipo 1/fisiopatologia , Sistema de Condução Cardíaco/fisiopatologia , Disfunção Ventricular Esquerda/fisiopatologia , 3-Iodobenzilguanidina , Fibras Adrenérgicas/diagnóstico por imagem , Agonistas Adrenérgicos beta , Adulto , Peso Corporal , Complexos Cardíacos Prematuros/fisiopatologia , Baixo Débito Cardíaco/etiologia , Volume Cardíaco/fisiologia , Cardiomiopatias/etiologia , Cardiomiopatias/fisiopatologia , Estudos de Casos e Controles , Diabetes Mellitus Tipo 1/complicações , Diabetes Mellitus Tipo 1/diagnóstico por imagem , Dobutamina , Ecocardiografia , Estimulação Elétrica , Exercício Físico , Feminino , Força da Mão , Sistema de Condução Cardíaco/diagnóstico por imagem , Humanos , Incidência , Modelos Lineares , Masculino , Contração Miocárdica/fisiologia , Esforço Físico , Cintilografia , Compostos Radiofarmacêuticos , Descanso , Volume Sistólico/fisiologia , Disfunção Ventricular Esquerda/diagnóstico por imagem , Disfunção Ventricular Esquerda/etiologia , Função Ventricular Esquerda/fisiologiaRESUMO
We report here for the first time the case of a symptomatic DMD carrier, who had a heart transplant for a severe dilated cardiomyopathy. Dystrophin immunohistochemistry, western blot and analysis of X-chromosome inactivation on leucocytes, and skeletal and cardiac muscle biopsies on the explanted heart were performed. The patient was a heterozygote for exons 50-52 deletion in the dystrophin gene. The number of dystrophin-deficient fibres in the heart was much higher than in skeletal muscle. On the other hand, the explanted heart showed a non-skewed pattern of X-chromosome inactivation, as in leukocytes and skeletal muscle. The adverse cardiac course may be explained by the absence of regeneration among cardiomyocytes.
Assuntos
Cardiomiopatia Dilatada/cirurgia , Transplante de Coração , Heterozigoto , Distrofias Musculares/complicações , Distrofias Musculares/genética , Adulto , Biópsia , Cardiomiopatia Dilatada/complicações , Cardiomiopatia Dilatada/metabolismo , Cardiomiopatia Dilatada/patologia , DNA/análise , Mecanismo Genético de Compensação de Dose , Distrofina/genética , Distrofina/metabolismo , Feminino , Humanos , Imuno-Histoquímica , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Distrofias Musculares/metabolismo , Distrofias Musculares/patologia , Miocárdio/metabolismoRESUMO
BACKGROUND: Identification of viable but hibernating myocardium remains a relevant issue in the current era of myocardial revascularization. Echocardiography can be helpful in detecting reversible contractile dysfunction and optimizing the selection of patients for coronary bypass surgery. METHODS AND RESULTS: Eighty-four consecutive candidates for bypass surgery with chronic multivessel coronary artery disease were screened, and 60 were included in this prospective study. Preoperative evaluation of a reversible contractile dysfunction in asynergic myocardial regions was performed by dobutamine infusion at 5 (low dose) and 10 (intermediate dose) microg x kg(-1) x min(-1) with each stage lasting at least 5 minutes; postextrasystolic potentiation (PESP), with a coupling interval ranging from 500 to 300 ms with a progressive 10-ms decrease; or a combination of both dobutamine infusion and PESP. Sensitivity (92% versus 86%) and predictive accuracy (89% versus 84%) were higher with PESP than dobutamine (P=.009 and P=.001, respectively), but the combination did not improve sensitivity or accuracy. Dobutamine induced ischemic dysfunction in 15% of patients at the intermediate dose; however, the low dose resulted in loss of sensitivity. CONCLUSIONS: PESP echocardiography is a useful and cost-effective method to identify viable myocardium in patients with multivessel coronary disease undergoing revascularization and is more sensitive and accurate than dobutamine infusion.
Assuntos
Complexos Cardíacos Prematuros/diagnóstico por imagem , Complexos Cardíacos Prematuros/fisiopatologia , Cardiotônicos , Ponte de Artéria Coronária , Dobutamina , Ecocardiografia , Coração/fisiopatologia , Adulto , Idoso , Feminino , Seguimentos , Previsões , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica , Período Pós-Operatório , Estudos Prospectivos , Resultado do TratamentoRESUMO
The presence of myocardial injury during non-surgical coronary revascularization has been evaluated by means of highly specific and sensitive biochemical markers. Troponin T, creatine kinase-MB isoenzyme mass concentration, and creatine kinase MB2/MB1 isoform ratio have been determined in 80 patients who underwent coronary revascularization with percutaneous transluminal coronary angioplasty (PTCA). Forty-five patients underwent balloon angioplasty, 15 rotational atherectomy, 10 directional atherectomy, and 10 elective coronary stenting. Serum concentration of the evaluated markers did not increase significantly after 57 uncomplicated revascularization procedures, including 15 rotablation procedures, nor after 8 PTCAs complicated by localized coronary type B and C dissections. Significant elevation of all markers above the upper limits of the reference interval (P < 0.05) was detected after occlusion of small side branches (< 0.5 mm diameter) in 5 patients. Creatine kinase MB2/MB1 isoform ratio was the earliest marker to increase. After recanalization of occluded vessels in 8/10 patients with 6-60 days old myocardial infarction only troponin T concentrations increased from a baseline of 0.28 microgram/l to a median peak of 0.80 microgram/l. This increase was statistically not significant (P = 0.12). In conclusion, myocardial damage was not detected following uncomplicated non-surgical revascularization obtained with different techniques. Markers of myocardial injury provide high sensitivity after small side branch occlusion.
Assuntos
Angioplastia Coronária com Balão/efeitos adversos , Aterectomia Coronária/efeitos adversos , Creatina Quinase/sangue , Miocárdio/metabolismo , Troponina/sangue , Idoso , Biomarcadores , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Isoenzimas , Masculino , Pessoa de Meia-Idade , Sensibilidade e Especificidade , Estatísticas não Paramétricas , Troponina TRESUMO
BACKGROUND: The long-term administration of oral anticoagulants to patients with mechanical heart valve prostheses is generally accepted. However, the appropriate intensity of oral anticoagulant treatment in these patients is still controversial. METHODS AND RESULTS: From March 1991 to March 1994, patients referred to the Padova Thrombosis Center who had undergone mechanical heart valve substitution at least 6 months earlier were randomly assigned to receive oral anticoagulants at moderate intensity (target INR = 3) or moderate-high intensity (target INR = 4). Principal end points were major bleeding, thromboembolism and vascular death. Minor bleeding was a secondary end-point. A total of 104 patients were assigned to the target 3 group and 101 to the target 4 group; they were followed for from 1.5 years to up 4.5 years (mean, 3 years). Principal end-points occurred in 13 patients in the target 3 group (4 per 100 patient-years) and in 20 patients in the target 4 group (6.9 per 100 patient-years). Major hemorrhagic events occurred in 15 patients, 4 in the target 3 group (1.2 per 100 patient-years) and 11 in the target 4 group (3.8 per 100 patient-years) (p = 0.019). The 12 recorded episodes of thromboembolism, 4 of which consisted of a visual deficit, were all transient ischemic attacks, 6 in the target 3 group (1.8 per 100 patient-years) and 6 in the target 4 group (2.1 per 100 patient-years). There were 3 vascular deaths in each group (0.9 and 1 per 100 patient-years for target 3 and target 4 groups, respectively). Minor bleeding episodes occurred 85 times (26 per 100 patient-years) in the target 3 group and 123 times (43 per 100 patient-years) in the target 4 group (p = 0.001). CONCLUSIONS: Mechanical heart valve patients on anticoagulant treatment who had been operated on at least 6 months earlier experienced fewer bleeding complications when maintained on a moderate intensity regimen (target INR = 3) than those on a moderate-high intensity regimen (target INR = 4). The number of thromboembolic events and vascular deaths did not differ between the two groups.
Assuntos
Anticoagulantes/uso terapêutico , Próteses Valvulares Cardíacas , Administração Oral , Adulto , Idoso , Anticoagulantes/administração & dosagem , Anticoagulantes/efeitos adversos , Relação Dose-Resposta a Droga , Feminino , Seguimentos , Próteses Valvulares Cardíacas/mortalidade , Hemorragia/induzido quimicamente , Hemorragia/epidemiologia , Humanos , Ataque Isquêmico Transitório/induzido quimicamente , Ataque Isquêmico Transitório/epidemiologia , Masculino , Pessoa de Meia-Idade , Tromboembolia/induzido quimicamente , Tromboembolia/epidemiologiaRESUMO
INTRODUCTION: Heart transplantation (HT) is a largerly accepted therapy for patients with refractory congestive heart failure. However, lack of donors imposes a rigorous choice among candidates for transplantation. Aim of this study was to identify retrospectively determinants for the selection of recipients. METHODS: Between december 1985 and december 1993 500 patients were listed for HT at the Department of Cardiovascular Surgery of the Padua University. Among United Network for Organ Sharing (UNOS) status II patients, 42 transplanted (group I) and 38 died waiting for a donor (group II) were chosen. The following parameters were collected at the time of insertion into the waiting list: sex, blood group, diagnosis, age, body surface area, natriemia, renal function, hepatic function, presence of ventricular arrhythmias, use of ACE-inhibitors, cardiac index, mean pulmonary pressure, mean wedge pressure, mean arterial pressure, central venous pressure, pulmonary arteriolar resistances, left ventricular ejection fraction. Also the time on waiting list until a final event (transplantation or death) was considered. RESULTS: Comparing the two groups the diagnosis of dilated cardiomyopathy (59.4% group I vs 36.8% group II; p = 0.04) and ejection fraction (26.4 +/- 9.1% group I vs 22.2 +/- 8.0% group II; p = 0.03) were the only variables statistically different. Multivaried analysis evidenced some parameters as independent predictors for HT. In detail, being listed for HT for more than 6 months lowered the probability to receive a heart to 0.34, while waiting for more than 12 months increased it to 2.64. Mean arterial pressure higher than 75 mmHg increased the probability for HT to 2.87, while an increase in mean pulmonary pressure of 5 mmHg lowered the probability to 0.80. An increase in the cardiac index of 0.5 l/m1/m2 lowered the probability to 0.61. A blood group other than 0 increased the possibility to 3.60, the basal surface area higher than 1.78 m2 lowered it to 0.306 and an ejection fraction higher than 22% increased it to 3.94. CONCLUSIONS: We can conclude that parameters which predict the outcome of patients listed for HT were not only size matching, blood group and waiting time, but also ejection fraction, arterial pressure and diagnosis.
Assuntos
Transplante de Coração , Seleção de Pacientes , Adulto , Idoso , Feminino , Cardiopatias/mortalidade , Cardiopatias/fisiopatologia , Cardiopatias/cirurgia , Hemodinâmica/fisiologia , Teste de Histocompatibilidade , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Doadores de TecidosRESUMO
The purpose of this paper is to review the history of the clinico-pathologic investigations performed at the University of Padua on an old morbid entity ("parchment heart"), which, in the 1960s, led to the clinical description of the disease, in the 1980s to the revival of the scientific interest, and in the mid 1990s to the understanding of the genetic background. All the steps of the progressive knowledge are reviewed: necropsy of young people who died suddenly, in vivo diagnosis by ECG, echocardiography, angiocardiography, endomyocardial biopsy, nuclear magnetic resonance, and diagnostic criteria. Familial occurrence with autosomic dominant transmission and various penetrance was documented. Gene defects were recently mapped both to chromosome 14q23-q24 and 1q42-q43, thus providing evidence for genetic heterogeneity. The pathologic substrates of arrhythmogenic right ventricular cardiomyopathy pointed to an acquired progressive myocardial atrophy with fibro-fatty replacement of dying myocytes. Nowadays the disease is definitively regarded as a primary myocardial disorder and it has been included in the revised WHO classification of cardiomyopathies.