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1.
Europace ; 18(9): 1406-10, 2016 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26589627

RESUMO

AIMS: This study presents and evaluates the impact of a new lowest-dose fluoroscopy protocol (Siemens AG), especially designed for electrophysiology (EP) procedures, on X-ray dose levels. METHODS AND RESULTS: From October 2014 to March 2015, 140 patients underwent an EP study on an Artis zee angiography system. The standard low-dose protocol was operated at 23 nGy (fluoroscopy) and at 120 nGy (cine-loop), the new lowest-dose protocol was operated at 8 nGy (fluoroscopy) and at 36 nGy (cine-loop). Procedural data, X-ray times, and doses were analysed in 100 complex left atrial and in 40 standard EP procedures. The resulting dose-area products were 877.9 ± 624.7 µGym² (n = 50 complex procedures, standard low dose), 199 ± 159.6 µGym² (n = 50 complex procedures, lowest dose), 387.7 ± 36.0 µGym² (n = 20 standard procedures, standard low dose), and 90.7 ± 62.3 µGym² (n = 20 standard procedures, lowest dose), P < 0.01. In the low-dose and lowest-dose groups, procedure times were 132.6 ± 35.7 vs. 126.7 ± 34.7 min (P = 0.40, complex procedures) and 72.3 ± 20.9 vs. 85.2 ± 44.1 min (P = 0.24, standard procedures), radiofrequency (RF) times were 53.8 ± 26.1 vs. 50.4 ± 29.4 min (P = 0.54, complex procedures) and 10.1 ± 9.9 vs. 12.2 ± 14.7 min (P = 0.60, standard procedures). One complication occurred in the standard low-dose and lowest-dose groups (P = 1.0). CONCLUSION: The new lowest-dose imaging protocol reduces X-ray dose levels by 77% compared with the currently available standard low-dose protocol. From an operator standpoint, lowest X-ray dose levels create a different, reduced image quality. The new image quality did not significantly affect procedure or RF times and did not result in higher complication rates. Regarding radiological protection, operating at lowest-dose settings should become standard in EP procedures.


Assuntos
Arritmias Cardíacas/cirurgia , Ablação por Cateter/métodos , Cineangiografia/métodos , Angiografia Coronária/métodos , Técnicas Eletrofisiológicas Cardíacas , Doses de Radiação , Exposição à Radiação/prevenção & controle , Radiografia Intervencionista/métodos , Adulto , Idoso , Arritmias Cardíacas/diagnóstico por imagem , Arritmias Cardíacas/fisiopatologia , Cateteres Cardíacos , Ablação por Cateter/efeitos adversos , Ablação por Cateter/instrumentação , Cineangiografia/efeitos adversos , Angiografia Coronária/efeitos adversos , Técnicas Eletrofisiológicas Cardíacas/efeitos adversos , Técnicas Eletrofisiológicas Cardíacas/instrumentação , Estudos de Viabilidade , Feminino , Fluoroscopia , Humanos , Masculino , Pessoa de Meia-Idade , Duração da Cirurgia , Exposição à Radiação/efeitos adversos , Radiografia Intervencionista/efeitos adversos , Estudos Retrospectivos , Fatores de Risco , Fatores de Tempo , Resultado do Tratamento
2.
Int J Cardiovasc Imaging ; 31(1): 7-9, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-25156690

RESUMO

Ventricular tachycardia and, more rarely, sudden cardiac death are potential complications affecting the long-term outcome after Tetralogy of Fallot (ToF) repair. Intraventricular septal scar, fibro-fatty substitution around infundibular resection and patchy myocardial fibrosis may provide anatomical substrates of abnormal depolarization and repolarization causing reentrant ventricular arrhythmias. Recently, three-dimensional electro-anatomical mapping (3D EAM) has allowed to investigate the electro-anatomical status of the right ventricle. Radiation exposure during cardiac electrophysiological procedures is still a major concern. We report the first case of 3D mapping of the right ventricle in a postoperative ToF patient performed with a new module of the CARTO® 3 System-the CARTOUnivu™ Module-that combines, simultaneously, fluoroscopic images or cine-angiographic sequences with 3D cardiac mapping to allow real-time visualization of the electrocatheter during the 3D EAM reconstruction. The same volume, previously evaluated with cardiac MRI, was mapped. A perfect match of the diastolic edges of the RV obtained either by cine-loop acquisition during contrast fluoroscopy and by the 3D EAM, was observed. The fluoroscopy time for 3D EAM was 10 s. In conclusion, CARTOUnivu™ Module can integrate, in real time, fluoroscopic images/cine-angiography in virtual biplane view and the 3D EAM allowing a contextual visualization of position and movement of all electrocatheters. This can further increase the accuracy of the 3D EAM in very complex-operated congenital heart diseases, even decreasing radiation exposure.


Assuntos
Cateterismo Cardíaco , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Cineangiografia , Técnicas Eletrofisiológicas Cardíacas , Ventrículos do Coração/cirurgia , Imageamento Tridimensional , Interpretação de Imagem Radiográfica Assistida por Computador , Taquicardia Ventricular/diagnóstico , Tetralogia de Fallot/cirurgia , Potenciais de Ação , Cateterismo Cardíaco/instrumentação , Cateteres Cardíacos , Técnicas Eletrofisiológicas Cardíacas/instrumentação , Desenho de Equipamento , Fluoroscopia , Ventrículos do Coração/diagnóstico por imagem , Ventrículos do Coração/fisiopatologia , Humanos , Imagem Multimodal , Valor Preditivo dos Testes , Taquicardia Ventricular/diagnóstico por imagem , Taquicardia Ventricular/fisiopatologia , Tetralogia de Fallot/diagnóstico por imagem , Tetralogia de Fallot/fisiopatologia , Resultado do Tratamento
3.
Circ Arrhythm Electrophysiol ; 5(4): 684-90, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-22773023

RESUMO

BACKGROUND: We describe a novel fluoroscopy coregistered, 4-dimensional catheter tracking technology (MediGuide Technology [MGT]) used for treatment of patients with atrial fibrillation. The aim of the study was to investigate (1) the feasibility of nonfluoroscopic catheter manipulation within dynamic left atrial chamber models; (2) the integration of the technology into an established electroanatomical mapping system; and (3) potential clinical impact. METHODS AND RESULTS: Forty-nine patients received atrial fibrillation ablation using MGT-enabled NavX-EnSite. Matched patients ablated with a conventional NavX-EnSite system served as a control group. MGT was used for the deployment of diagnostic catheters within preacquired cine loops, for nonfluoroscopic chamber mapping within dynamic angiograms, and for 4-dimensional tagging of anatomical landmarks. Integration with the electroanatomical mapping system allowed correction of field distortions and a reference tool to detect and correct map shifts. Catheter ablation was done without MGT because the ablation catheter was not MGT enabled. MGT worked safely and stably in all 49 patients. Catheter deployment within the preacquired cine loops was successfully performed in 45 of 49 (92%) patients. Catheter tracking within dynamic left atrial angiograms allowed nearly nonfluoroscopic creation of NavX-EnSite geometries with subsequent computed tomography model registration in all 49 patients. Overall, MGT significantly reduced total procedural fluoroscopy time (median [quartiles]) from 31 minutes (25, 43 minutes) to 16 minutes (10, 23 minutes) and irradiation dose from 14 453±7403 to 7363±5827 cGy*cm(2) (mean±SD), respectively (P<0.001). CONCLUSIONS: MGT is a tracking technology that allows 4-dimensional visualization of dedicated catheters within moving chamber models. Integration of the MGT with an established electroanatomical mapping system provided algorithms to facilitate mapping in the electroanatomical mapping system environment. As a first measurable clinical impact, MGT was able to reduce fluoroscopy exposure by nearly 50%.


Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Cineangiografia , Campos Eletromagnéticos , Cirurgia Assistida por Computador/métodos , Idoso , Algoritmos , Fibrilação Atrial/diagnóstico , Estudos de Casos e Controles , Ablação por Cateter/instrumentação , Catéteres , Distribuição de Qui-Quadrado , Eletrocardiografia Ambulatorial , Técnicas Eletrofisiológicas Cardíacas , Estudos de Viabilidade , Feminino , Fluoroscopia , Alemanha , Humanos , Interpretação de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Cirurgia Assistida por Computador/instrumentação , Resultado do Tratamento
4.
Circ Arrhythm Electrophysiol ; 4(6): 838-43, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-21984444

RESUMO

BACKGROUND: The addition of a mitral isthmus (MI) block line after pulmonary vein isolation could lead to a favorable outcome of catheter ablation in patients with atrial fibrillation (AF). However, it is sometimes tough to create a complete MI block line, and the cooling effect because of the local coronary flow may prevent the creation of a successful MI block line. METHODS AND RESULTS: This study enrolled 81 AF patients in whom the creation of an MI block line was attempted in those with persistent or pacing-inducible AF after pulmonary vein isolation. A local coronary artery (LCA) across the MI block line was observed in 43 (53%) of 81 patients, and a bidirectional MI block was successfully accomplished in 53 (65%) of 81 patients, at the estimated MI line. The ratio of a successful MI block line was significantly lower in the patients with an LCA than in those without an LCA (42% versus 92%; P<0.001). The mean diameter of the coronary sinus (0.59 ± 0.18 versus 0.82 ± 0.22 cm; P<0.001) and length of the estimated MI line (33.4 ± 9.9 versus 29.4 ± 7.1 mm; P=0.032) were significantly shorter in the patients with a successful MI block line than in those without a successful MI block line. In the multivariable analysis, an LCA at the MI and a larger coronary sinus diameter were independent risk factors for an unsuccessful MI block line. CONCLUSIONS: Local coronary flow at the MI is associated with an increased incidence of an unsuccessful MI block line.


Assuntos
Fibrilação Atrial/cirurgia , Ablação por Cateter/efeitos adversos , Circulação Coronária , Seio Coronário/fisiopatologia , Sistema de Condução Cardíaco/cirurgia , Valva Mitral/cirurgia , Idoso , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Ablação por Cateter/métodos , Distribuição de Qui-Quadrado , Cineangiografia , Angiografia Coronária , Seio Coronário/diagnóstico por imagem , Ecocardiografia Transesofagiana , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Feminino , Sistema de Condução Cardíaco/fisiopatologia , Humanos , Japão , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Valva Mitral/fisiopatologia , Flebografia , Veias Pulmonares/fisiopatologia , Veias Pulmonares/cirurgia , Medição de Risco , Fatores de Risco , Falha de Tratamento
5.
Congenit Heart Dis ; 6(5): 479-83, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21518426

RESUMO

The ablation of atrioventricular (AV) nodal reentrant tachycardia in patients with the Senning or Mustard procedure is quite challenging because these atrial baffle procedures isolate the AV node from systemic venous access. Cryoablation is commonly utilized for AV nodal slow pathway modification in patients with structurally normal hearts. The cryoablation technique offers the advantage of monitoring AV nodal conduction during lesions, with the ability to terminate a lesion prior to permanent injury to the AV node. This case describes the successful cryoablation of the slow AV nodal pathway via the transbaffle approach in a patient with d-transposition of the great arteries status post the Mustard procedure.


Assuntos
Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Criocirurgia , Taquicardia por Reentrada no Nó Atrioventricular/cirurgia , Transposição dos Grandes Vasos/cirurgia , Adulto , Cineangiografia , Técnicas Eletrofisiológicas Cardíacas , Feminino , Humanos , Taquicardia por Reentrada no Nó Atrioventricular/diagnóstico , Taquicardia por Reentrada no Nó Atrioventricular/etiologia , Resultado do Tratamento
6.
Catheter Cardiovasc Interv ; 76(5): 769-73, 2010 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-20506170

RESUMO

OBJECTIVES: The objective of this study was to demonstrate the safety and efficacy of a new transseptal needle design with a radiofrequency (RF) tip combined with the ease of use of the needle configuration. BACKGROUND: RF transseptal puncture to enter the left heart, with a RF wire-catheter system is a successful technique in patients with complex access using a standard transseptal needle. METHODS: The RF transseptal needle (NRG™ Transseptal Needle; Baylis Medical, Montreal, Canada) was designed for RF percutaneous transseptal access to the left heart. Eight pigs underwent transvenous cardiac catheterization with baseline intracardiac electrograms and right atrial pressure waveforms. Transseptal RF puncture was performed followed by left atrial pressure waveform monitoring. RESULTS: An intracardiac electrogram was recorded in each animal while dragging the needle tip from the superior caval vein across the atrial septum and into the inferior caval vein. Contrast staining of the atrial septum was accomplished in all animals, with subsequent RF septal puncture. After 0.1 sec, impedance increased from 300 to 1,200 Ohms with the creation of a vapor layer, and voltage increased steadily to a threshold of 230 volts over the first 0.4 sec. This dielectric breakdown results in tissue vaporization and tissue perforation. The needle's location within the left atrium was confirmed by the pressure waveform and contrast injection. Repeated RF punctures with the NRG™ was compatible with various manufactures transseptal sheaths. CONCLUSION: RF puncture of the interatrial septum using the NRG™ Transseptal Needle facilitates an alternative effective technique to enter the left atrium. © 2010 Wiley-Liss, Inc.


Assuntos
Cateterismo Cardíaco/instrumentação , Ablação por Cateter/instrumentação , Agulhas , Animais , Função do Átrio Esquerdo , Cateterismo Cardíaco/efeitos adversos , Ablação por Cateter/efeitos adversos , Cineangiografia , Técnicas Eletrofisiológicas Cardíacas , Desenho de Equipamento , Septos Cardíacos/diagnóstico por imagem , Hemodinâmica , Teste de Materiais , Modelos Animais , Punções , Suínos , Fatores de Tempo
8.
Yan Ke Xue Bao ; 11(1): 57-60, 1995 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8575610

RESUMO

BACKGROUND: There were some reports in China about Huoxue-Huayu therapy on retinal vein occlusion (RVO), but prospective and systematic studies are very few. The curative effect and mechanism of this therapy on RVO have not been reported previously. METHODS: 80 patients with RVO were randomly divided into 2 groups, Fundus III (group A) and urokinase group (group B). Group A was treated by Fundus III oral liquid (a composite herbal recipe for Huoxue-Huayu or invigoration of blood circulation and reduction of blood stasis) 10ml/time P.O. t.i.d. The treatment course was 1 mouth. Group B was treated by urokinase. The urokinase that produced in China was used 10,000 u + 5% glucose 500ml/day i.v. drip for 5 days in a course, the rest 5 days going on another course. The total treatment courses lasted 1 month, too. RESULTS: The visual acuity in group A was remarkably improved while that in group B did not change. The extravasated retinal blood was evidently absorbed in 92.7% of the cases in group A and in 66.7% of those in group B. The difference was significant. Fundus III also improved the retinal circulation, decreased the whole blood viscosity and fibrinogen and reduced leakage of the retinal capillaries. The total effective rates were 83.7% in group A and 53.7% in group B with significant statistical difference between the 2 groups (P < 0.01). CONCLUSION: Fundus III may alleviate retinal edema and necroses, improve the recovering of visual acuity, the retinal microcirculation, the rate of absorbing of retinal haemorrhage and treat RVO, and the curative effect is better than urokinase.


Assuntos
Medicamentos de Ervas Chinesas/uso terapêutico , Fibrinolíticos/uso terapêutico , Oclusão da Veia Retiniana/tratamento farmacológico , Acuidade Visual , Adulto , Idoso , Cineangiografia , Feminino , Angiofluoresceinografia , Humanos , Masculino , Pessoa de Meia-Idade , Ativador de Plasminogênio Tipo Uroquinase/uso terapêutico
9.
Comput Methods Programs Biomed ; 38(2-3): 91-100, 1992 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-1458869

RESUMO

A computer-based educational system for the study of cardiovascular imaging is described. This system, based on HyperCard * and a standard Macintosh II, integrates hypertext retrieval, computer graphics, sound, and medical images into a single interactive environment stored on a standard hard disk. This 'hypermedia' approach allows arbitrary complexity coupled with direct, immediate, easy traversal of the images and related text, which provides the opportunity for students to move at their own pace, choose their own direction through the material and repeat as often as desired. Storage on magnetic medium allows for easy updating with new studies and material in order to keep pace with advances in medical imaging technology. The system could be mastered onto CD-ROM for ease of distribution if so desired. The system includes a tutorial on the basics of digital image representation and example studies from cineangiography, nuclear medicine, echocardiography and magnetic resonance imaging of the heart. Quantitative techniques for evaluation of left ventricular function are explained using computer graphics overlays on the original medical images. Color encoded functional images are also included as an aid to visualization of ventricular performance data. The system has proven useful as a primer for digital imaging in cardiology prior to specific case study in a traditional mentor relationship.


Assuntos
Cardiologia/educação , Doenças Cardiovasculares/diagnóstico , Instrução por Computador/normas , Diagnóstico por Imagem , Processamento de Imagem Assistida por Computador , CD-ROM , Cineangiografia , Instrução por Computador/métodos , Ecocardiografia , Humanos , Imageamento por Ressonância Magnética , Microcomputadores , Cintilografia , Software
10.
Int J Card Imaging ; 6(2): 117-33, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2097305

RESUMO

Animal experiments demonstrated a significant suppressive effect of various calcium channel blockers on the formation of atherosclerotic lesions. Therefore, a prospective, placebo-controlled, randomized, double blind multicenter study was performed to investigate the inhibitory influence of the calcium channel blocker nifedipine (80 mg/day) on the progression of coronary artery disease in man. Study endpoints were changes of coronary morphology documented by coronary angiography with particular respect to the formation of new coronary stenoses. In 348 out of 425 patients included in the study, coronary angiograms were repeated after three years. The angiograms were standardized by induction of a maximal coronary vasodilation with high doses of nitrates and by using absolutely identical angiographic projections. Quantitative analysis of coronary cineangiograms was performed with the computer-assisted contour detection system CAAS. Parameters were mean and minimal diameter of all segments and minimal stenosis diameter, percent diameter stenosis, length and plaque area of all stenoses. Continuous intake of study medication was registered in 282 patients, 134 on nifedipine and 148 patients on placebo. In these patients, a total of 3808 coronary segments with 893 stenoses (greater than or equal to 20% diameter reduction in at least one angiographic projection) were compared on the baseline and follow-up cineangiograms. The changes in all angiographic parameters analyzed averaged over all patients by considering all angiographic projections analyzed, indicated significant progression of the disease (p less than 0.006). The average changes in all parameters were even about three times more profound, when in the individual patients only the respective projections indicating the maximal changes were considered for the calculation (p less than 0.001). However, with neither of these two analysis modes, the differences in progression between the treatment groups were statistically significant. In the follow-up angiograms, a total of 196 new coronary lesions (185 stenoses, 11 occlusions) were found at previously normal arterial sites. In patients on nifedipine, an average of only 0.58 new lesions per patient were detected versus 0.80 lesions per patient on placebo (-27%; p = 0.031). INTACT is the first prospective angiographic trial on the progression of coronary artery disease using computer-assisted quantitative coronary angiography in such a high number of patients. All parameters analyzed indicated significant progression of coronary artery sclerosis. Nifedipine had no influence on the progression of preexisting coronary stenoses, but inhibited significantly the formation of new angiographically recognizable lesions. Further prospective coronary angiographic trials with calcium channel blockers using a comparably exact method are needed to confirm the results of this study.


Assuntos
Angiografia Coronária , Doença da Artéria Coronariana/tratamento farmacológico , Processamento de Imagem Assistida por Computador , Nifedipino/uso terapêutico , Cineangiografia/métodos , Doença da Artéria Coronariana/diagnóstico por imagem , Método Duplo-Cego , Humanos , Estudos Prospectivos
11.
Chest ; 93(3): 485-92, 1988 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3277802

RESUMO

Changes induced by nifedipine (10 mg sublingually) in the residual luminal diameter of significant (greater than 50 percent) coronary lesions were assessed angiographically in 69 patients with effort-induced angina (group 1), in 22 patients with mixed angina (group 2), and in 14 patients with Prinzmetal's angina (group 3). These changes were related to the clinical response to treatment with the same drug, as evaluated through diary records and Holter monitoring in the mixed (spontaneous component) and Prinzmetal forms and through exercise testing in effort-induced and mixed (effort-associated component) angina. In groups 1 and 2, segments of stenotic vessels showed either an increase or decrease or no change in diameter with the calcium antagonist; in group 3, the majority of the lesions had compliant portions which invariably responded with dilatation. Nifedipine failed to improve cases with exertional (20 percent [14/69] unchanged; 19 percent [13/69] worsened) and mixed (41 percent [9/22] exacerbated) forms; 100 percent of the 14 patients with the Prinzmetal form had relief of the anginal episodes. In group 1, the response to exercise tests was dissociated from the short-term vasomotor pattern, and the pressure-rate product failed to explain the clinical results. Forty-five percent (ten) of the patients in group 2 showed significant short-term widening of critical stenoses, as well as obvious improvement; patients who did worse with treatment in this group had reacted to nifedipine with narrowing of critical stenoses. These data suggest that the response to nifedipine of classic effort-induced angina is probably the net result of an interaction of changes in myocardial oxygen consumption and supply; coronary vasomotion has a role in mixed angina, and influences of nifedipine may be either favorable or unfavorable; stenotic lesions in the Prinzmetal form are quite sensitive to the relaxant action of calcium blockade, and this probably represents a background to the highly positive clinical response to treatment.


Assuntos
Angina Pectoris Variante/tratamento farmacológico , Angina Pectoris/tratamento farmacológico , Vasos Coronários/efeitos dos fármacos , Nifedipino/uso terapêutico , Esforço Físico , Angina Pectoris/diagnóstico por imagem , Angina Pectoris Variante/diagnóstico por imagem , Cineangiografia , Ensaios Clínicos como Assunto/métodos , Angiografia Coronária , Quimioterapia Combinada , Eletrocardiografia , Teste de Esforço , Humanos , Monitorização Fisiológica , Fatores de Tempo
12.
Cuad. Hosp. Clín ; 34(1): 33-37, 1988. tab
Artigo em Espanhol | LILACS | ID: lil-138377

RESUMO

Se analizaron los hallazgos Eccocardiograficos en siete pacientes con diagnostico clinico, Radiologico y Electrocardiografico de Enfermedad de Ebstein, tres de estos pacientes fueron sometidos a Cateterismo Cardiaco y Cineangiocardiografia. Las alteraciones Ecocardiograficas encontradas e interpretadas como criterios diagnosticos de Enfermedad de Ebstein en vigencia del examen clinico, fueron: 1) Retraso del cierre de la Valvula Tricuspide respecto a laValvula Mitral, mayor a 50 miliseg. b) Registro simultaneo de la Valvula Mitral Tricuspide desde posiciones alejadas del borde esternal izq. c) Amplitud incrementada del movimiento diatolico de la valva anterior de la Tricuspide, d) Morfologia alterada de la valva anterior de la Tricuspide, e) incremento aparente de las dimensiones de Ventriculo derecho, f) Movimiento anormal del Neptum Intraventricular. Se concluye que la Ecocardiografia incrementa las posibilidades diagnosticas de esta Cardiopatia compleja, asimismo se llama la atencion sobre la elevada incidneica de la Enfermedad de Ebstein en nuestra casuistica.


Assuntos
Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Anomalia de Ebstein/diagnóstico , Anomalia de Ebstein/reabilitação , Anomalia de Ebstein/terapia , Bolívia , Cineangiografia , Ecocardiografia , Cateterismo Cardíaco , Diagnóstico Clínico , Função Ventricular/fisiologia
13.
Circulation ; 76(6): 1232-44, 1987 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-3677348

RESUMO

The effect of pacing-induced ischemia on early left ventricular filling and regional myocardial lengthening was studied in 11 patients with coronary artery disease (CAD) and six control patients with normal coronary arteriograms. All of the 11 patients with CAD developed typical anginal pain during pacing tachycardia, and in the postpacing beat, the left ventricular end-diastolic pressure (LVEDP) rose from 13 +/- 4 to 26 +/- 4 mm Hg (mean +/- SD, p less than .01), the relaxation time constant increased from 43 +/- 9 to 59 +/- 7 msec (p less than .01), and the ejection fraction diminished from 62.1 +/- 6.7 to 51.6 +/- 10.6% (p less than .01). However, the peak rate of early left ventricular filling (LVPF) obtained from frame-by-frame analysis of left ventriculograms and the LVPF normalized for the stroke volume and for the end-diastolic volume did not change significantly. In the ischemic segment, the peak rate of lengthening (PL) decreased by 45% with ischemia, and the PL normalized for the end-diastolic segment length decreased by 42%. However, the PL normalized for the extent of systolic shortening did not change. In the control segment there was a tendency for these three variables to increase, but the changes were not statistically significant. The time difference from the PL to the LVPF increased significantly in the ischemic segment (31 +/- 28 vs 75 +/- 48 msec, p less than .05). Although the LVEDP rose slightly but significantly from 9 +/- 3 to 12 +/- 5 mm Hg (p less than .05) in the control patients in the postpacing beat, the other global hemodynamic variables and the variables of regional myocardial dynamics did not change. The administration of nifedipine in six patients with CAD resulted in the disappearance or diminution of anginal pain even with the same duration and rate of pacing and was associated with restoration of global systolic function and regional myocardial shortening and lengthening in the ischemic segment. In the control segment, the three variables of segmental lengthening increased with administration of nifedipine. Thus, the segmental myocardial lengthening rate decreased with ischemia due to a decrease in segmental shortening and impairment of myocardial distensibility. The LVPF did not decrease with ischemia despite impairment in isovolumetric relaxation, accentuation of asynchrony in left ventricular filling, and a decrease in the PL in the ischemic segment because of an increase in the PL in the nonischemic segment secondary to an increase in left ventricular filling pressure.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Doença das Coronárias/fisiopatologia , Coração/fisiopatologia , Contração Miocárdica , Nifedipino/uso terapêutico , Adulto , Idoso , Pressão Sanguínea , Cateterismo Cardíaco , Estimulação Cardíaca Artificial , Cineangiografia , Doença das Coronárias/tratamento farmacológico , Feminino , Coração/efeitos dos fármacos , Frequência Cardíaca , Humanos , Processamento de Imagem Assistida por Computador , Masculino , Pessoa de Meia-Idade , Nifedipino/farmacologia , Volume Sistólico
14.
Am J Cardiol ; 55(13 Pt 1): 1545-9, 1985 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-4003297

RESUMO

Atrial and ventricular arrhythmias were characterized by ambulatory electrocardiography in 31 patients with nonischemic mitral regurgitation (MR), 17 of whom had echocardiographic evidence of mitral valve prolapse (MVP) and 14 of whom had other causes of MR. Frequent and complex arrhythmias were common and equally prevalent in each MR subgroup, whether or not MVP was present. Multiform ventricular ectopy was found in 77% (24 of 31), ventricular couplets in 61% (19 of 31), and ventricular salvos or ventricular tachycardia in 35% (11 of 31) of patients with MR. Arrhythmias in patients with MR were significantly more prevalent than in 63 patients with MVP who had no evidence of MR. Among patients with MVP, excess arrhythmias associated with MR were most striking with respect to frequent ventricular premature complexes (41% with MR vs 3% without MR), multiform ventricular ectopic activity (88% vs 43%), ventricular couplets (65% vs 6%), and ventricular salvos or ventricular tachycardia (35% vs 5%) (p less than 0.005 for each comparison). These data demonstrate that complex arrhythmias are common in patients with nonischemic MR irrespective of etiology, and that these arrhythmias are more strongly associated with hemodynamically important MR than with MVP alone.


Assuntos
Arritmias Cardíacas/etiologia , Insuficiência da Valva Mitral/complicações , Prolapso da Valva Mitral/complicações , Adulto , Idoso , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/fisiopatologia , Cineangiografia , Digitalis , Ecocardiografia , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Insuficiência da Valva Mitral/diagnóstico , Insuficiência da Valva Mitral/fisiopatologia , Prolapso da Valva Mitral/diagnóstico , Prolapso da Valva Mitral/fisiopatologia , Plantas Medicinais , Plantas Tóxicas
15.
Radiology ; 154(2): 495-8, 1985 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-2981425

RESUMO

An ultrasonic sector scanner and pulsed Doppler flowmeter were combined to measure portal venous velocity in 19 patients with portal hypertension and compared with cineangiographic mapping of a droplet of oil released into the portal vein. In 12 patients, measurements were made before and after pitressin [7] or ranitidine [5]. With the Doppler method, maximum basal portal venous velocity was 17.0 +/- 3.9 cm/sec., while average cineangiographic velocity was 8.5 +/- 2.7 cm/sec., a significant difference (p less than 0.001). After pitressin, velocity decreased to 8.3 +/- 2.7 cm/sec. with the Doppler method and 3.6 +/- 1.0 cm/sec. with cineangiography. Ranitidine did not produce an appreciable change. Doppler and cineangiographic velocity measurements exhibited significant correlation over a wide range of values (r = 0.960). Thus the pulsed Doppler method may give accurate values of portal venous velocity if they are corrected to cineangiographic values. Flow can be calculated from velocity and the cross-sectional area of the portal vein as measured on the sonogram. The Doppler method is simple and noninvasive and is particularly useful in studying changes in portal hemodynamics.


Assuntos
Cineangiografia , Veia Porta/fisiologia , Ultrassonografia , Adulto , Velocidade do Fluxo Sanguíneo , Feminino , Humanos , Hipertensão Portal/fisiopatologia , Óleo Iodado , Masculino , Pessoa de Meia-Idade , Veia Porta/diagnóstico por imagem , Ranitidina , Vasopressinas
16.
Am J Med ; 71(4): 667-75, 1981 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7282755

RESUMO

The calcium blocking agent nifedipine was shown to protect the isolated left ventricle against the development of altered diastolic compliance during severe global ischemia. To assess the influence of nifedipine during myocardial ischemia in human subjects, we studied the effect of nifedipine (20 mg sublingually) on the hemodynamic response to pacing tachycardia (heart rate 66 +/- 4 to 143 +/- 4 beats per minute) in 17 patients with multivessel coronary artery disease. Typical anginal pain occurred in all patients during pacing tachycardia before nifedipine, but in only 3 of 17 patients during pacing after nifedipine. In 11 patients a significant (greater than or equal to 5 mm Hg) increase in postpacing left ventricular end-diastolic pressure (LVEDP, 15 +/- 2 mm Hg to 28 +/- 2 mm Hg, p less than 0.01) developed, and was associated with an upward shift of the left ventricular diastolic pressure-volume curve. In these patients, pretreatment with nifedipine did not alter resting LVEDP or aortic pressure, but did attenuate or abolish the increase n LVEDP and the shift in left ventricular diastolic pressure-volume curves after pacing tachycardia to the same rate and for the same duration. The antianginal effect of nifedipine was not associated with a reduction in contractility, because there was no change in LV + dp/dt after nifedipine. However, the increase in left ventricular systolic pressure achieved in response to pacing tachycardia was less after nifedipine. We conclude that nifedipine favorably modifies the symptomatic and hemodynamic response to pacing tachycardia in patients with coronary artery disease. The mechanism is uncertain and could involve a direct myocardial effect, peripheral vasodilation, coronary vasodilation or a combination of these effects.


Assuntos
Bloqueadores dos Canais de Cálcio/uso terapêutico , Doença das Coronárias/tratamento farmacológico , Nifedipino/uso terapêutico , Piridinas/uso terapêutico , Taquicardia/tratamento farmacológico , Cineangiografia , Ventrículos do Coração/efeitos dos fármacos , Hemodinâmica/efeitos dos fármacos , Humanos , Taquicardia/fisiopatologia
17.
Radiol Technol ; 51(4): 491-3, 1980.
Artigo em Inglês | MEDLINE | ID: mdl-7355198

RESUMO

Coronary angiography is an important procedure, and the best quality radiographs possible are essential to accurate diagnosis. Aside from the technical factors necessary to produce good images, the ability of the patient to breathe properly greatly influences the radiographic outcome. The breathing technique described here has been found effective, and teaching patients how to do it is an integral part of the technologist's role in the examination.


Assuntos
Cineangiografia/métodos , Angiografia Coronária , Exercícios Respiratórios , Humanos , Intensificação de Imagem Radiográfica , Respiração
19.
Buenos Aires; s.n; 1974. s.p ilus, tab, graf. (83592).
Monografia em Espanhol | BINACIS | ID: bin-83592

RESUMO

Creemos haber demostrado que en la actualidad no es razonable hablar de la evolución natural de la cardioapatía isquémica en su conjunto. Es posible identificar una serie de cuadros clínicos con diferentes modalidades evolutivas que confirmen características determinadas a cada uno de los grupos. Lo antedicho avala la propuesta de nuestra clasificación de la cardiapatía isquémica sintomática en base al angor, esta división es sin duda perfectible pero, hemos comenzado a aplicarla hace cuatro años y hasta ahora funciona a entera satisfacción. Todavía hoy se lee y se escucha en los congresos nacionales e internacionales que muy poco se conoce de la evolución natural de la ateroesclerosis coronaria en la angina de pecho estable. Es indudable que mucho se ha progresado en el conocimiento de la misma desde los trabajos iniciales analizados aquí y basados solamente en la clasificación clínica de los pacientes, con todos los errores que ello llevaba involucrado. No obstante dieron una idea general del panorama a abarcar y en nuestros días la introducción de la cine coronario angiografía por Sones abrió todo un camino para conocer la base anatómica precisa de la enfermedad... (TRUNCADO)(AU)


Assuntos
Humanos , Masculino , Feminino , História Natural das Doenças , Infarto do Miocárdio/complicações , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/terapia , Isquemia Miocárdica/classificação , Isquemia Miocárdica/etiologia , Isquemia Miocárdica/mortalidade , Isquemia Miocárdica/prevenção & controle , Isquemia Miocárdica/terapia , Angina Pectoris/classificação , Angina Pectoris/diagnóstico , Angina Pectoris/cirurgia , Angina Pectoris/terapia , Angina Instável/cirurgia , Angina Instável/terapia , Angina Pectoris Variante/cirurgia , Angina Pectoris Variante/etiologia , Angina Pectoris Variante/fisiopatologia , Angina Pectoris Variante/terapia , Doença da Artéria Coronariana/complicações , Morte Súbita , Ergometria , Sinais e Sintomas , Evolução Clínica , Avaliação Nutricional , Prognóstico , Seguimentos , Hemodinâmica , Eletrocardiografia , Cineangiografia , Diagnóstico Diferencial , Angiografia Coronária
20.
Buenos Aires; s.n; 1974. s.p ilus, tab, graf.
Monografia em Espanhol | BINACIS | ID: biblio-1205548

RESUMO

Creemos haber demostrado que en la actualidad no es razonable hablar de la evolución natural de la cardioapatía isquémica en su conjunto. Es posible identificar una serie de cuadros clínicos con diferentes modalidades evolutivas que confirmen características determinadas a cada uno de los grupos. Lo antedicho avala la propuesta de nuestra clasificación de la cardiapatía isquémica sintomática en base al angor, esta división es sin duda perfectible pero, hemos comenzado a aplicarla hace cuatro años y hasta ahora funciona a entera satisfacción. Todavía hoy se lee y se escucha en los congresos nacionales e internacionales que muy poco se conoce de la evolución natural de la ateroesclerosis coronaria en la angina de pecho estable. Es indudable que mucho se ha progresado en el conocimiento de la misma desde los trabajos iniciales analizados aquí y basados solamente en la clasificación clínica de los pacientes, con todos los errores que ello llevaba involucrado. No obstante dieron una idea general del panorama a abarcar y en nuestros días la introducción de la cine coronario angiografía por Sones abrió todo un camino para conocer la base anatómica precisa de la enfermedad... (TRUNCADO)


Assuntos
Masculino , Feminino , Humanos , Angina Instável/cirurgia , Angina Instável/terapia , Angina Pectoris Variante/cirurgia , Angina Pectoris Variante/etiologia , Angina Pectoris Variante/fisiopatologia , Angina Pectoris Variante/terapia , Angina Pectoris/cirurgia , Angina Pectoris/classificação , Angina Pectoris/diagnóstico , Angina Pectoris/terapia , Angiografia Coronária , Avaliação Nutricional , Cineangiografia , Diagnóstico Diferencial , Doença da Artéria Coronariana/complicações , Eletrocardiografia , Ergometria , Evolução Clínica , Hemodinâmica , História Natural das Doenças , Infarto do Miocárdio/complicações , Infarto do Miocárdio/mortalidade , Infarto do Miocárdio/terapia , Isquemia Miocárdica/classificação , Isquemia Miocárdica/etiologia , Isquemia Miocárdica/mortalidade , Isquemia Miocárdica/prevenção & controle , Isquemia Miocárdica/terapia , Morte Súbita , Prognóstico , Seguimentos , Sinais e Sintomas
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