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1.
J Evol Biol ; 20(5): 1799-808, 2007 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-17714297

RESUMO

We sequenced 1077 bp of the mitochondrial cytochrome b gene and 511 bp of the nuclear Apolipoprotein B gene in bicoloured shrew (Crocidura leucodon, Soricidae) populations ranging from France to Georgia. The aims of the study were to identify the main genetic clades within this species and the influence of Pleistocene climatic variations on the respective clades. The mitochondrial analyses revealed a European clade distributed from France eastwards to north-western Turkey and a Near East clade distributed from Georgia to Romania; the two clades separated during the Middle Pleistocene. We clearly identified a population expansion after a bottleneck for the European clade based on mitochondrial and nuclear sequencing data; this expansion was not observed for the eastern clade. We hypothesize that the western population was confined to a small Italo-Balkanic refugium, whereas the eastern population subsisted in several refugia along the southern coast of the Black Sea.


Assuntos
Musaranhos/classificação , Migração Animal , Animais , Apolipoproteínas B/química , Apolipoproteínas B/genética , Sequência de Bases , Evolução Biológica , Citocromos b/química , Citocromos b/genética , DNA Mitocondrial/química , Europa (Continente) , Geografia , Oriente Médio , Dados de Sequência Molecular , Filogenia , Dinâmica Populacional , Análise de Sequência de DNA , Musaranhos/anatomia & histologia , Musaranhos/genética , Isolamento Social
2.
Int J Cardiol ; 79(2-3): 151-7, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-11461736

RESUMO

BACKGROUND: Electrical cardioversion of atrial fibrillation (AF) to sinus rhythm is associated with transient left atrial dysfunction and this phenomenon may lead to thrombus formation and embolic stroke. Delay of atrial mechanical function recovery may be related to ventricular diastolic function. OBJECTIVE: This study examined the effects of left ventricular diastolic function as well as the multiple clinical factors on the recovery of atrial systolic function after cardioversion for atrial fibrillation. METHODS: A total of 44 patients (28 male, 16 female, 61+/-18 years) with chronic AF (> or =1 month) underwent electrical cardioversion. Deceleration time of early filling wave (pre-CV EDT) on transmitral inflow obtained by using Doppler echocardiography before cardioversion and serial transmitral inflow Doppler variables were recorded through a 1 week study period in all patients. Various clinical (age, gender, the duration of AF) and echocardiographic variables (pre-CV EDT, left atrial dimension, left ventricular ejection fraction) were tested for an association with peak atrial filling wave velocity (VA) on day 1, 3 and 7 after cardioversion. RESULTS: EDT measured before cardioversion had a strong linear correlation with peak VA on every echocardiographic evaluation after cardioversion (Regression coefficient (R)=0.69, P<0.001; R=0.78, P<0.001 and R=0.83, P<0.001, on day 1, day 3 and day 7, respectively). The effect of left ventricular ejection fraction on peak VA was weaker than those of EDT. The duration of AF showed an inverse association with the recovery of atrial function, but this lost on multivariate analysis. None of the other parameters significantly correlated with peak VA after cardioversion. CONCLUSION: The recovery of atrial mechanical function after cardioversion, as assessed by peak VA on transthoracic Doppler echocardiography is mainly associated with the left ventricular diastolic function as measured by EDT, whereas the left ventricular systolic function relatively a small effect on this outcome. The duration of AF does not have any association with peak VA, possibly if it is chronic.


Assuntos
Fibrilação Atrial/terapia , Função do Átrio Esquerdo , Cardioversão Elétrica , Recuperação de Função Fisiológica , Análise de Variância , Fibrilação Atrial/diagnóstico por imagem , Doença Crônica , Ecocardiografia Doppler de Pulso , Feminino , Hemodinâmica , Humanos , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Volume Sistólico
3.
Acta Cardiol ; 55(5): 289-94, 2000 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11103828

RESUMO

OBJECTIVE: Determination of viability in the infarction zone in the early post Ml period is an important parameter in clinical decision making. METHODS: In an attempt to compare the places of low-dose dobutamine echocardiography (LDDE) and thallium-201 reinjection SPECT (TI-SPECT) in the determination of viability in dyssynergic myocardial segments, 17 patients (mean age: 54.6 +/- 12.8 years, 16 male, 1 female) with a recent myocardial infarction and an uneventful early clinical course underwent both tests within 5-13 days of infarction. The 16-segment model was utilised to evaluate the left ventricular wall motion and each segment was graded as 1) normokinetic, 2) hypokinetic, 3) akinetic and 4) dyskinetic or aneurysmal on a 4-scale basis. A dyssynergic segment of myocardium was considered to be viable by LDDE if it showed an improvement in wall motion of at least one grade with low-dose dobutamine infusion (10 microg/kg/min). On the other hand, mild to moderate (< 50%) fixed perfusion defects and reversible (at least a 10% improvement in perfusion on either redistribution or reinjection images) severe (50% or more) perfusion defects were considered positive for viability by TI-SPECT. RESULTS: Of the 76 segments with resting dyssynergy (10 dyskinetic/aneurysmal, 33 akinetic, 33 hypokinetic), 51 (67%) were shown to be viable by LDDE and 61 (80%) by TI-SPECT. There was an agreement of 76% (p = 0.03, K = 0.63) between the two methods. CONCLUSION: This study disclosed a moderate degree of agreement between LDDE and TI-SPECT for the determination of viability in dyssynergic myocardial segments in the early post-myocardial infarction period.


Assuntos
Cardiotônicos , Dobutamina , Ecocardiografia , Infarto do Miocárdio/diagnóstico por imagem , Radioisótopos de Tálio , Tomografia Computadorizada de Emissão de Fóton Único , Adulto , Cardiotônicos/administração & dosagem , Dobutamina/administração & dosagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radioisótopos de Tálio/administração & dosagem
5.
Int J Cardiol ; 63(3): 281-6, 1998 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-9578356

RESUMO

Widened dispersion of refractoriness has been considered to lead to an increase in atrial vulnerability. In this study, we obtained simultaneous monophasic action potential recordings by 2 special catheters from 2 different loci in the right atrium in 9 normal subjects (Group 1) and in 7 patients with paroxysmal atrial fibrillation (Group 2). We measured action potential duration at 50% (APD50) and 90% (APD90) repolarization from both loci in the right atrium during steady-state through one of the two catheters. The differences between APD50 and APD90 recorded by the two catheters were designated as dispersion of APD50 and dispersion of APD90, respectively. While, the mean APD50 and APD90 were 149.7+/-16.9 and 228.3+/-44.7 ms respectively in Group 1, the corresponding values for Group 2 were 145.7+/-33.5 and 213.5+/-53.1 ms. The difference between the 2 groups was not statistically significant. However, the dispersion of APD50 and APD90 were 13.8+/-13.8 and 10.0+/-9.7 ms in Group 1 and 42.8+/-19.6 and 57.1+/-32.4 in Group 2, respectively and the difference between the 2 groups for both measurements was statistically significant (P<0.01). Another finding was a high correlation between age and dispersion of APD90 in the whole population studied (r=0.82, P<0.001). With these findings, although one can not derive the conclusion that patients with paroxysmal atrial fibrillation have a greater dispersion of repolarization, our finding of increasing dispersion of repolarization with age could be an explanatory factor for the increased prevalence of atrial fibrillation with advanced age.


Assuntos
Fibrilação Atrial/fisiopatologia , Sistema de Condução Cardíaco/fisiopatologia , Potenciais de Ação , Adulto , Fatores Etários , Feminino , Humanos , Masculino
6.
Angiology ; 49(3): 193-201, 1998 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9523542

RESUMO

It has previously been shown that leukocyte elastase is involved in the pathogenesis of atherosclerosis. Few studies have addressed the relation between leukocyte elastase concentrations and coronary artery disease (CAD). The authors investigated (1) the clinical significance of leukocyte elastase determination in the diagnosis of CAD and (2) the relation between plasma leukocyte elastase concentration and lesion morphology. The study included 185 subjects (140 men, 45 women) who underwent coronary angiography during investigation of chest pain; 135 had coronary stenosis (Group I) and 50 had nonstenotic coronaries (Group II). Among Group I patients, those with simple atheromatous plaques were distinguished from those with complex plaques. Elastase concentrations in Group I were greater than in Group II (57.1 +/- 1.16 micrograms I[-1] vs 27.6 +/- 1.0 microgram, I[-1], P<0.001), and greater in complex plaque patients than in those with simple plaques (64.5 +/- 1.24 micrograms I[-1] vs 45.9 +/- 1.01 micrograms I[-1], P<0.001). Logistic regression analysis showed (1) that elastase concentration, age, and sex had independent value for prediction of CAD and (2) that among Group I patients, the risk of complex plaques was greatest for those with high elastase concentration. These results suggest that plasma leukocyte elastase concentration is a sensitive diagnostic marker of CAD and that high values of elastase may indicate the presence of complex atheromatous plaques.


Assuntos
Ensaios Enzimáticos Clínicos , Doença das Coronárias/diagnóstico , Elastase de Leucócito/sangue , Plasma/enzimologia , Angina Pectoris/diagnóstico , Angina Instável/diagnóstico , Biomarcadores/sangue , Ensaios Enzimáticos Clínicos/métodos , Ensaios Enzimáticos Clínicos/estatística & dados numéricos , Angiografia Coronária , Feminino , Humanos , Técnicas Imunoenzimáticas/instrumentação , Contagem de Leucócitos , Lipídeos/sangue , Masculino , Pessoa de Meia-Idade , Neutrófilos , Sensibilidade e Especificidade
7.
Pacing Clin Electrophysiol ; 21(1 Pt 1): 134-6, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9474660

RESUMO

Presented here is a 39-year-old male patient with no structural heart disease but a ventricular tachycardia with right bundle branch block morphology and right axis deviation, which is responsive to adenosine. The ventricular tachycardia was initiated by ventricular pacing, shown to originate from the mid-anterior free wall region of the left ventricle and terminated by adenosine. Radiofrequency current application at a site where presumed P potentials were recorded eliminated the tachycardia, a finding that suggests that the origin of the tachycardia may be closely related to the anterior fascicle.


Assuntos
Adenosina/uso terapêutico , Taquicardia/fisiopatologia , Disfunção Ventricular Esquerda/fisiopatologia , Adulto , Bloqueio de Ramo/fisiopatologia , Bloqueio de Ramo/terapia , Estimulação Cardíaca Artificial , Ablação por Cateter , Eletrocardiografia , Humanos , Masculino , Taquicardia/tratamento farmacológico , Taquicardia/terapia , Disfunção Ventricular Esquerda/tratamento farmacológico , Disfunção Ventricular Esquerda/terapia
8.
Cardiology ; 88(4): 328-32, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9197426

RESUMO

In this study, we tried to disclose certain electrocardiogram (ECG) criteria that might be useful in the classification of posteroseptal accessory atrioventricular pathways as right and left in patients with pre-excitation in whom the accessory pathway localization was verified by subsequent successful ablation. Twenty such patients with posteroseptal accessory pathways (mean age 34.9 +/- 9.8; 11 male, 9 female) were included in the study. Localization of the accessory pathway was right posteroseptal in 13 (65%) and left posteroseptal in 7 (35%). Common to all these 20 patients with posteroseptal accessory pathways was a QRS polarity positive in lead L1 and negative in leads D3, aVL. In patients with right posteroseptal accessory pathways, QRS polarity was negative in lead V1 in all and positive in lead V2 in 90%. On the other hand, none of the patients with left posteroseptal accessory pathways showed negative QRS polarity in lead V1. In conclusion, these findings strongly suggest that in patients with pre-excitation, a QRS polarity negative in lead V1 and positive in lead V2 is an important surface ECG finding that signifies right-sided localization of a posteroseptal accessory pathway. In cases with left posteroseptal accessory pathways, QRS polarity in leads V1 and V2 has been found to be either biphasic or positive.


Assuntos
Nó Atrioventricular/fisiopatologia , Ablação por Cateter/métodos , Eletrocardiografia/métodos , Septos Cardíacos/inervação , Síndrome de Wolff-Parkinson-White/fisiopatologia , Adulto , Nó Atrioventricular/cirurgia , Fascículo Atrioventricular/fisiopatologia , Feminino , Septos Cardíacos/fisiopatologia , Humanos , Masculino , Síndrome de Wolff-Parkinson-White/cirurgia
9.
Turk J Pediatr ; 39(3): 421-7, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9339124

RESUMO

Ectopic atrial tachycardia (EAT) is a rare but reversible cause of dilated cardiomyopathy (DCMP). The diagnosis and the definite control of the arrhythmia are essential for the regression of DCMP. Unfortunately, conventional antiarrhythmic drugs usually fail to control the arrhythmia, and the results of surgery or direct current ablation are suboptimal. Recently, radiofrequency (RF) catheter ablation has been evolving as a safe and effective therapy for EAT. This report describes the RF ablation treatment of a 14-year-old boy with DCMP secondary to chronic EAT. Activation mapping was used for the purpose of identifying the focus origin located just anterior to the coronary sinus os. RF energy applied at this focus successfully terminated the tachycardia. No complications related to the procedure were observed. RF ablation not only caused elimination of the EAT but also led to improvement in left ventricular function as early as two weeks after the procedure, and complete resolution of DCMP in three months.


Assuntos
Cardiomiopatia Dilatada/etiologia , Ablação por Cateter , Taquicardia Atrial Ectópica/terapia , Adolescente , Doença Crônica , Ecocardiografia , Eletrocardiografia , Humanos , Masculino , Taquicardia Atrial Ectópica/complicações , Taquicardia Atrial Ectópica/diagnóstico
10.
Jpn Heart J ; 38(1): 127-32, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9186288

RESUMO

In this report, we describe a case of sustained ventricular tachycardia of right ventricular outflow tract origin, induced by dobutamine infusion in a patient with symptomatic, frequent ventricular premature depolarizations but no documented clinical ventricular tachycardia. Radiofrequency catheter ablation abolished not only the ventricular tachycardia itself, but also the frequent ventricular premature depolarizations responsible for all the symptomatology. In conclusion, provocation by catecholamine infusion may have a place in the search for an alternative to antiarrhythmic therapy in patients with isolated, frequent and symptomatic ventricular premature depolarizations.


Assuntos
Ablação por Cateter , Taquicardia Ventricular/diagnóstico , Complexos Ventriculares Prematuros/cirurgia , Adulto , Bloqueio de Ramo/fisiopatologia , Eletrocardiografia Ambulatorial , Feminino , Humanos , Complexos Ventriculares Prematuros/complicações
13.
Nephrol Dial Transplant ; 11(10): 2050-4, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8918721

RESUMO

BACKGROUND: The present study was performed to assess the value of ambulatory blood pressure monitoring (ABPM) in determining the adequacy of blood pressure (BP) control, and its relationship to echocardiographic findings in haemodialysis (HD) patients. METHODS: We studied 40 non-diabetic adult patients who had been on regular HD treatment for a median duration of 43 months. Twenty-four-hour ABPM was performed using a non-invasive ABP monitor (Pressurescan, ERKA). Casual BP (cBP) was defined as the average of two measurements obtained at two HD sessions, one preceding and one following the ABP recordings, and was calculated for both the predialysis and postdialysis phases. Two-dimensional and M-mode echocardiography were performed in each patient to determine interventricular septal thickness (IVS), left ventricular posterior wall thickness (LVPW), left ventricular fractional shortening (FS), and left ventricular mass index (LVMI). RESULTS: According to average 24-h BP levels, 50% of the patients had systolic hypertension (HT) (> 139 mmHg), and 72.5% had diastolic HT (> 87 mmHg), while only 25% had been diagnosed as HT by cBP measurements (P < 0.01 and P < 0.0001 respectively). Diurnal variation in BP was not present in about 80% of the patients. Echocardiography was normal in only four patients (10%). LVMI and LV wall thickness were correlated to ABPM data better than to cBP measurements. Using stepwise linear regression analysis, LVMI and IVS were positively correlated with systolic BP load (P < 0.0001 and P = 0.0001 respectively), and LVPW was positively correlated with night-time systolic BP level (P < 0.001). CONCLUSIONS: ABPM is necessary to assess the adequacy of BP control, and is well correlated to end-organ damage of HT in HD patients.


Assuntos
Monitorização Ambulatorial da Pressão Arterial , Ecocardiografia , Diálise Renal , Adolescente , Adulto , Diástole , Feminino , Humanos , Hipertensão/complicações , Hipertensão/diagnóstico por imagem , Hipertensão/fisiopatologia , Falência Renal Crônica/complicações , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Sístole
14.
Cathet Cardiovasc Diagn ; 39(1): 80-1, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8874953

RESUMO

A 66-yr-old woman was admitted to our clinic with signs and symptoms suggesting either pulmonary embolism or pneumonia. Subsequently she was diagnosed as having pneumonia, but since pulmonary artery pressure was high on echocardiography, pulmonary angiography was performed to exclude the possibility of pulmonary embolism. No findings suggestive of pulmonary embolism were evident on pulmonary angiogram, but there was a fistulous connection between the left pulmonary artery and the innominate vein. To our knowledge, this report represents the first case of a fistula between the pulmonary artery and a systemic vein.


Assuntos
Fístula Arteriovenosa , Veias Braquiocefálicas/anormalidades , Artéria Pulmonar/anormalidades , Idoso , Angiografia , Fístula Arteriovenosa/complicações , Fístula Arteriovenosa/diagnóstico por imagem , Veias Braquiocefálicas/diagnóstico por imagem , Feminino , Humanos , Hipertensão Pulmonar/etiologia , Artéria Pulmonar/diagnóstico por imagem
15.
Am J Cardiol ; 77(1): 96-8, 1996 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-8540469

RESUMO

The highest frequency of AF in RHD occurs in those with mitral stenosis, mitral regurgitation, and tricuspid regurgitation in combination. AF, while occurring in 29% of patients with isolated mitral stenosis and in 16% with isolated mitral regurgitation, is an infrequent finding (1%) in patients with aortic valvular disease. Left atrial diameter by univariate analysis, and age and left atrial diameter by multivariate analysis have been shown to be the most important parameters to determine the occurrence of AF in patients with RHD.


Assuntos
Fibrilação Atrial/etiologia , Doenças das Valvas Cardíacas/complicações , Cardiopatia Reumática/complicações , Adolescente , Adulto , Fibrilação Atrial/diagnóstico por imagem , Ecocardiografia , Feminino , Doenças das Valvas Cardíacas/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Prevalência , Estudos Retrospectivos , Cardiopatia Reumática/diagnóstico por imagem , Fatores de Risco
17.
J Electrocardiol ; 28(3): 199-208, 1995 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-7595122

RESUMO

Data on the correlation of coronary artery disease (CAD) and electrocardiographic findings are, except for Q waves, still controversial. The purpose of this study was to determine whether QRS complex notching and slurring (N&S) is of significant value as a diagnostic discriminator in the detection of CAD. This study comprised 500 consecutive patients aged between 24 and 81 years (mean, 53.4 years) who underwent coronary angiography because of chest pain. Patients were evaluated for CAD, angiographic evidence of myocardial infarction (MI), N&S, and abnormal Q waves. Of these 500 patients, 418 had CAD, and 370 of these had significant (> or = 70%) coronary artery obstruction. The remaining 82 patients had normal coronary arteries. The data revealed that the distribution of N&S in the patients with or without CAD was similar in both the inferior and limb leads (P > .05). But the percentage of N&S in more than two contiguous limb leads was higher in the patients with CAD than in the patients without CAD. Notching and slurring in at least one limb lead was found to be of no value in the diagnosis of MI, of wall motion abnormalities, and of significant obstruction. Notching and slurring in the anterior leads is more sensitive but less specific than abnormal Q waves in the same leads in the detection of significant obstruction, anterior MI, and anterior wall motion abnormalities. Notching and slurring in the anterior leads has as much importance as abnormal anterior Q waves in the detection of angiographic evidence of anterior infarct, of anterior wall motion abnormalities, and of significant coronary artery obstruction.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Doença das Coronárias/diagnóstico , Eletrocardiografia , Adulto , Idoso , Idoso de 80 Anos ou mais , Doença das Coronárias/fisiopatologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
18.
Rev Port Cardiol ; 14(2): 115-21, 103, 1995 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-7766435

RESUMO

The differential diagnosis of tachycardias with a long RP interval is reviewed and the methods of treatment of these arrhythmias catheter ablation are described. Electrocardiographic and electrophysiologic criteria for the correct diagnosis of atrial tachycardia, circus movement tachycardia using retrogradely an accessory pathway with decremental conduction properties and the uncommon form of atrioventricular nodal reentrant tachycardia are discussed. First results of our institution of radiofrequency catheter ablation of atrial tachycardias and circus movement tachycardias using retrogradely an accessory pathway with decremental conduction properties are presented. We concluded that both electrocardiographic and electrophysiologic criteria give a better understanding of the mechanism and arrhythmic site which are important markers for a safe and successful ablation procedure.


Assuntos
Ablação por Cateter , Taquicardia/diagnóstico , Taquicardia/cirurgia , Diagnóstico Diferencial , Eletrocardiografia , Eletrofisiologia , Humanos , Taquicardia/fisiopatologia
19.
Angiology ; 43(6): 477-81, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1595942

RESUMO

Nifedipine, a calcium-channel-blocking agent, was administered orally to 44 untreated patients (Group A) and sublingually to 51 untreated patients (Group B) who had a diastolic blood pressure more than 90 mm Hg and systolic blood pressure more than 140 mm Hg. The mean pretreatment systolic and diastolic blood pressure values were 185.3 +/- 26.0 and 115.1 +/- 13.4 mm Hg in Group A patients and 193.6 +/- 23.1 and 118.1 +/- 14.1 mm Hg in Group B patients respectively (p greater than 0.05). The hypotensive activity of nifedipine was observed at the tenth minute in both groups. Mean systolic and diastolic pressures were 168.9 +/- 23.7 and 101.9 +/- 14.2 mm Hg in Group A and 170.6 +/- 26.2 and 103.0 +/- 15.8 mm Hg in Group B, (p less than 0.001) Diastolic blood pressures dropped under 100 mm Hg at the twentieth minute in both groups. Maximal reduction of blood pressure was observed at the fortieth minute in both groups and the degree of reduction in blood pressure was also the same (mean systolic and diastolic blood pressures: 143.7 +/- 22.1 and 86.9 +/- 11.7 in Group A and 148.7 +/- 21.4 and 91.7 +/- 17.0 in Group B (p less than 0.05). The authors conclude that sublingual nifedipine administration is not superior to oral nifedipine administration (in capsular form) in the acute treatment of hypertension.


Assuntos
Hipertensão/tratamento farmacológico , Nifedipino/administração & dosagem , Doença Aguda , Administração Oral , Administração Sublingual , Avaliação de Medicamentos , Emergências , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nifedipino/uso terapêutico , Resultado do Tratamento
20.
Angiology ; 40(9): 844-8, 1989 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-2764312

RESUMO

A patient with resting heart rate over 100 beats per minute (bpm) displayed 1.5-2 mm ST segment depression in her ECG during daily activities. She had unprovoked further increase in her heart rate up to 145 bpm, and during these episodes, her ECG displayed further ST segment depression up to 3 mm and of 0.12 second duration. An organic cause could not be found to explain her sinus tachycardia. Results of all laboratory investigations, including coronary angiography, were normal. It was observed that during an episode of reflex vagotonia, when her heart rate was below 95 bpm, her previously depressed ST segments became isoelectric. With the thought that this patient's ST segment depression was rate-dependent, carotid sinus massage was performed, and when the heart rate slowed to 95 bpm her depressed ST segments became isoelectric. The same response was accomplished with beta blockers. Sympathetic hyperactivity was thought to be the most likely mechanism of ST segment depression in this patient. A critical increase in heart rate caused these ECG abnormalities.


Assuntos
Eletrocardiografia , Frequência Cardíaca , Taquicardia Sinusal/diagnóstico , Taquicardia Supraventricular/diagnóstico , Adulto , Dor no Peito/diagnóstico , Dor no Peito/etiologia , Dor no Peito/fisiopatologia , Doença Crônica , Angiografia Coronária , Feminino , Ventrículos do Coração/diagnóstico por imagem , Humanos , Estresse Psicológico/complicações , Estresse Psicológico/fisiopatologia , Sistema Nervoso Simpático/fisiopatologia , Taquicardia Sinusal/etiologia , Taquicardia Sinusal/fisiopatologia
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