[On the electrical manifestations of some heart diseases associated with ventricular preexcitation]. / Manifestaciones eléctricas de alteraciones miocárdicas asociadas a preexcitación ventricular.

Electro-Vectorcardiographic curves, corresponding some heart diseases, must be analyzed in the light of the ventricular depolarization sequence, as well as on the heart's position and rotation. A more than 30-msec interval between the end of the initial slurring (delta) and the vertex of the R wave in the left unipolar leads or the main axis of the vectorcardiographic ventricular curves, allows us to infer the coexistence of left ventricular hypertrophy. On the other hand, segmental irregularities or distorsions of the electric curves suggest the presence of a limited myocardial zone unable to be activated. Extensive or multiple deformations of these curves are more suggestive of a diffuse myocardial damage. Sometimes signs of preexcitation, due to a pharmacological action, can also appear.

Influence of infarct-related artery patency on the indexes of parasympathetic activity and prevalence of late potentials in survivors of acute myocardial infarction.

OBJECTIVES: The purpose of this study was to determine whether infarct-related coronary artery patency influences myocardial electrical stability as measured by the prevalence of late potentials or heart rate variability. BACKGROUND: Several studies have suggested that loss of vagal activity is associated with an increased incidence of arrhythmic death after myocardial infarction. METHODS: A short-duration, high resolution electrocardiogram (ECG) was performed before hospital discharge in 175 patients with a first myocardial infarction. Seventy-three patients received thrombolytic therapy. All patients underwent coronary angiography. Coronary occlusion was defined as minimal or no anterograde flow. Eighty-eight patients (50.3%) had an occluded infarct-related artery. Sixty-two healthy subjects served as control subjects to determine the normal range of heart rate variability. RESULTS: Comparison between the control group and patients without patency of the infarct-related artery in the time domain and spectral analyses revealed in the latter patients a reduced heart rate variability (p < 0.0001) and a lower power spectrum density in both the 0.05- to 0.15-Hz band (p < 0.0001) and the 0.15- to 0.35-Hz band (p < 0.0001). The heart rate variability in patients with late potentials was lower than in those with a normal signal-averaged ECG. Those patients with spontaneous or thrombolysis-induced reperfusion have less occurrence of late potentials and higher parasympathetic activity than do patients with a closed artery. CONCLUSIONS: This study suggests that the patency of the infarct-related artery determines both the absence of late potentials and the preservation of vagal tone and may explain the reduction in mortality induced by thrombolytic therapy in myocardial infarction.

Active vs passive rhythms as an explanation of bigeminal rhythm with similar P waves.

We describe the criteria for differential diagnosis between 3:2 sinoatrial block from atrial bigeminy due to an ectopic focus in the sinus or parasinus zone. In the 3:2 sinoatrial block the RR interval of the basic rhythm is similar to the short R-R interval of the paired rhythm. In atrial bigeminy, the R-R interval of the basic rhythm is similar to the long R-R interval of the paired rhythm.

Endoscopic ligature of the sphenopalatine artery for severe posterior epistaxis.

OBJECTIVE: To present our experience with endoscopic ligature of the sphenopalatine artery in the treatment of severe posterior epistaxis of patients who had previously undergone conservative procedures. METHODS: Eleven patients with severe posterior epistaxis were treated during a 25-month period with an endoscopic ligature of the sphenopalatine artery. The basic principle of the surgical technique is to identify the branches of the sphenopalatine artery through an endoscopic endonasal approach and to apply a titanium clip under direct vision. RESULTS: The endoscopic ligature of the sphenopalatine artery was performed unilaterally in 10 patients and bilaterally in 1 patient, with a total of 12 ligatures. It was possible to identify the sphenopalatine artery in all cases with a successful outcome using this surgical technique alone. CONCLUSION: Endonasal endoscopic ligature of the sphenopalatine artery has been an effective surgical technique for treating severe posterior epistaxis.

On the electrocardiographic diagnosis of biventricular infarctions.

To diagnose posterior and anterior biventricular infarctions it is necessary to record from right and left thoracic and high abdominal unipolar leads. These supplementary leads are dependable, can be repeated as many times as needed and show the evolution from signs of myocardial injury to those of dead tissue (Q waves of 0.04 sec or more). This electrocardiographic evolution increases the diagnostic value of the electrical exploration, since the injury current can be observed also in other conditions. The diagnosis of right ventricular infarction can be established even in the presence of RBBB. Signs of a dead zone in the free right ventricular wall are more frequently observed in posterior biventricular infarctions than in anterior ones. In these cases, the signs of subepicardial injury are more accentuated in the right thoracic unipolar leads than in V3, indicating anterior right ventricular involvement. These signs are also observed in experimental studies made in animals. This electrocardiographic exploration opens a wide field for the diagnosis of myocardial infarction, particularly in biventricular involvement, including old myocardial scars, and in discarding signs of pericarditis manifested only by the upward displacement of the ST segment. A review of the medical literature concerning diagnosis of biventricular infarctions is presented.

Effects of verapamil in ventricular tachycardias. An experimental and clinical study.

To determine the effect of verapamil in ventricular tachycardias, we performed an experimental and clinical study. Experimental ventricular tachycardias (VT) were produced in dog hearts with minute aconitine crystals introduced into the periphery of a left ventricular area, damaged by intramural injection of 1.0-1.5 ml phenol. The response of these tachycardias to 0.2 mg/kg verapamil was analyzed. Verapamil was infused into the superior vena cava over 15-20 min. Leads II, aVL, intraventricular right and left unipolar records, as well as one of the superior vena cava, were registered under control conditions, in the presence of VT, and after application of verapamil. Recordings were obtained at constant intervals, waiting for the recovery of sinus rhythm (SR) and the posterior reappearance of tachycardia. Experiments were performed for 6 to 8 h under continuous infusion of Hartmann's solution. Throughout these periods, variations in systemic systolic pressure were recorded. From 75 animals submitted to this treatment, 30 (40%) recovered transiently the SR, whereas the drug exerted no antiarrhythmic effect in 19 (25%), and arterial systolic pressure fell importantly in 10 (13%) animals. In two more groups, of 15 dogs each, the VT response to verapamil was compared with the response to lidocaine and flecainide. Endovenous verapamil (5-10 mg) was administered to 10 patients, coursing with VT and having a structurally normal heart, after this arrhythmia was induced by electrical stimulation. The response to verapamil was satisfactory in nine patients (90%), in which VT originated in the septal and apical regions of the left ventricle. Verapamil seems to be effective in experimental and clinical ventricular tachycardias related to calcium-dependent potentials, in which the sustaining mechanism could either be triggered activity or reentry.

[Usefulness of superficial electrocardiogram in the diagnosis of narrow QRS tachycardias: correlation with intracavitary electrocardiograms]. / Utilidad del electrocardiograma de superficie para el diagnóstico de las taquicardias con QRS estrecho: correlación con los registros intracavitarios.

INTRODUCTION AND OBJECTIVES: The electrocardiogram is an important tool to diagnose tachycardias. The sequence of analysis of the superficial electrocardiogram was evaluated for the diagnosis of supraventricular tachycardias with narrow QRS complexes (<= 110 ms) establishing correlation with intracavitary electrograms. PATIENTS AND METHODS: Between November 1996-October 1998, 674 electrophysiological studies were revised. 173 cases were selected, during which supraventricular tachycardias were inducted. In each study, the superficial electrocardiographic leads were correlated with the intracavitary electrograms during tachyarrhythmias. The P waves were located with respect to the R waves, the R-T or T-R' intervals, and the T waves, and relations between atrioventricular and ventriculoatrial intervals were established with the P-R' and R-P intervals, respectively, in the electrocardiogram. RESULTS: 107 patients were female. Upon locating the P waves in the electrocardiogram, in each supraventricular tachycardia we observed: a) P waves coincided with the R waves: 30 typical nodal reentries; b) P waves between R and T waves: 95 orthodromic atrioventricular reentries, 27 nodal reentries, 1 atrial tachycardia; c) P waves between T and R' waves: 4 nodal reentries, 5 orthodromic atrioventricular reentries, 7 atrial tachycardias, and

[Influence of the permeability of the artery responsible for the infarction on the variability of heart rate and late potentials. Its importance in the risk stratification after myocardial infarction]. / Influencia de la permeabilidad de la arteria responsable del infarto sobre la variabilidad de la frecuencia cardíaca y potenciales tardíos. Su importancia en la estratificación del riesgo postinfarto de miocardio.

The use of the heart rate variability for the study of the Autonomic nervous system has been well established. We analyzed late potentials and heart rate variability in 29 control patients and in 102 consecutive patients with a first myocardial infarction. The data obtained were analyzed with both, the medical treatment (thrombolysis and beta-blockers) and the patency of the infarct related vessel. Patients with an infarct had diminished vagal tone as compared with the control group. Those patients with occluded related arteries showed higher incidence of late potentials; interestingly patients with late potentials also had diminished vagal tone. Without looking at the patency of the infarct related artery, thrombolitic and betablocker therapy did not have any effect on vagal tone. All the variables were correlated with the patency of the infarct related artery. Those patients with patent arteries had a preservation of the vagal tone; this was independent of the treatment received and the presence of late potentials. We concluded that the patency of the infarct related artery determines the absence of late potentials and preservation of the vagal tone. This might be one of the mechanisms of how thrombolitic therapy decreases the incidence of cardiac death.

The rational approach to the electrical exploration of the heart.

A rational approach is inevitable in any scientific activity. Such an approach is opposed not only to irrationality, at all inadmissible in scientific thinking, but also to empiric reasoning. Many years ago, Sodi Pallares introduced the rational method in the electrical exploration of the heart based on experimental findings obtained in his laboratory. This method has progressively been accepted and used with good results for diagnoses and has led to logical therapeutic inferences. To confirm the results from the logical interpretation of electrical tracings, we present some examples of its application in three fields: arrhythmias, myocardial infarction, and left ventricular hypertrophy. In the studied cases--two with tachycardia, one with a posterior infarct, and two with left ventricular hypertrophy--a very satisfactory correlation has been observed between the electrical exploration findings and those obtained through direct examination of the heart. It is desirable, and even profitable, to analyze in this way the electrical tracings to get as close as possible to reality, rejecting the stereotyped aspects of a simple routine exploration, which often induce errors and lead to some fallacious asseverations.

[Sudden death in intermittent Wolff Parkinson White syndrome]. / Muerte súbita en el síndrome de Wolff Parkinson White intermitente.

Sudden death is a rare condition in asymptomatic patients with asymptomatic intermittent Wolff Parkinson syndrome (WPW); for this reason it is believed that these patients should not undergo to radiofrequency ablation. We report an asymptomatic 44 year old man who developed ventricular fibrillation with a pre-excited RR interval less than 200 msec during atrial fibrillation, as a first manifestation of WPW syndrome. The Holter monitoring showed intermittent pre-excitation at low heart rate (70 bpm). During the electrophysiological study a successfully radiofrequency catheter ablation of a right posteroseptal accessory pathway was performed. We concluded that intermittent pre-excitation may not be used to identify patients who are at risk of sudden death. Radiofrequency catheter ablation should be recommended in those patients with a very high success rate, and a low incidence of serious complications.

[Ventricular tachycardia associated with isolated right ventricular dysfunction as indicator of arrhythmogenic dysplasia of the right ventricle]. / Taquicardia ventricular asociada a disfunción del ventrículo derecho aislada como indicador de displasia arritmogénica del ventrículo derecho.

We report the case of a 21 year-old patient with arrhythmogenic right ventricular dysplasia manifested by episodes of QRS tachycardia greater than 0.12 sec and isolated dysfunction of the right ventricle. The patient treated with amiodarone however, the tachycardia episodes persisted. The surface electrocardiogram showed left branch block with the axis down, which suggested a right ventricle origin, and was therefore considered an arrhythmogenic dysplasia. Echocardiography and cardioangiography showed alterations in the anatomy of the outflow tract of the right ventricle. A myocardial gammagraphy revealed no perfusion alterations. The endomyocardial biopsy showed perivascular fibrosis. An electrophysiology study was performed, stimulating the outflow tract of the right ventricle, which induced two types of ventricular tachycardias, one of them identical to that recorded clinical. The patient was treated with sotalol, and has been being free of ventricular tachycardia episodes for 18 months of follow-up. We consider that this entity should be studied in a systematic way in those patients with ventricular tachycardia originated in the outflow of the right ventricle and with primary cardiac illness.

[Trans-surgical ablation of atrial flutter in patients treated with closure of atrial septal defect. Pilot project]. / Ablación transquirúrgica del flutter atrial en pacientes sometidos a cierre de comunicación interauricular. Estudio piloto.

Atrial flutter is one of the most common arrhythmias in patients with atrial septal defect, after surgery 14% of patients can develop it and may be associated with high morbidity. In this study we performed prophylactic and therapeutic ablation of atrial flutter during atrial septal closure surgery drawing 4 lines; line 1, isthmus cavo-tricuspid, the area between the inferior vena cava and the tricuspid ring; line 2, the area between coronary sinus ostium and inferior vena cava; line 3, the area between tricuspid valve annulus and coronary sinus ostium; and line 4, the area between lateral atriotomy and atrial septal defect. Twenty-one patients were included, 6 (28.5%) patients had atrial flutter before surgery and 15 (71.4%) were in sinus rhythm. There were no new cases of atrial flutter, but at six months follow up 2 (33.3%) patients recidivated with atrial flutter. One patient developed high degree atrio-ventricular block and a pacemaker had to be implanted. Older age at the time of surgery and high systolic pulmonary pressure were significantly higher in those patients with atrial flutter before surgery and in patients with arrhythmias recurrence. Ablation of atrial flutter during atrial septal closure surgery can be a good option for the treatment and prevention of atrial arrhythmias, but more studies are still needed.

[Radiofrequency ablation and simultaneous insertion of an Amplatzer device in a patient with atrial septal defect and nodal reentry tachycardia]. / Ablación con radiofrecuencia y colocación simultánea de un dispositivo Amplatzer en un paciente con comunicación interatrial y taquicardia por reentrada intranodal.

The association of AV nodal reentry tachycardia and interatrial septal defect has not been described previously. This article reports a 47-year-old woman with an atrial septal defect (ostium secundum) and history of palpitations without documental tachycardia through resting and ambulatory electrocardiography. Rapid atrial pacing under the influence of isoproterenol, during an electrophysiology study, elicited and AV nodal reentry tachycardia of the common type. Successful radiofrequency catheter ablation was performed targeting the slow pathway. Immediately an Amplatzer device was used for closure of the septal defect. Both procedures were successful and without complications. What makes this case unusual is that both interventional procedures were performed during the same session.

[The Einthoven's electrocardiograph after 100 years]. / A los 100 años del electrocardiógrafo de Einthoven.

The initial studies about the "irritability" of animal tissues by iatrophysic and iatromechanic scientists are reviewed. These studies led to discover the so called animal electricity envisaged by Luigi Galvani in the XVIII century and demonstrated by Carlo Matteucci and his followers in the XIX. Beginning with the Galvani's "reoscopic" frog, which allowed to assess the electrical current in a qualitative sense, it was possible to arrive, at the beginnings of the XX century, to the string electrocardiograph presented by Willem Einthoven in 1901. This opened the way that led to fabrication of ever more sophisticated instruments until the present systems of endocardial mapping by magnetic technology or by multipolar catheters, which permit to quickly identify the site of origin or the spreading ways of a tachycardia for their ablation with radio-frequency. Intracardiac echocardiography is also employed to define the anatomy of right atrium, during intracardiac cartography, in order to establish the most adequate sites for ablation. On the other hand, a logic i.e. rational, method for the interpretation of results from the electrical exploration of the heart has been developed. This one was introduced by Frank N. Wilson in Ann Arbor and has been fittingly applied by Demetrio Sodi Pallares in Mexico. Important diagnostic advances and notable therapeutic inferences have been derived from these latter developments.

[Increase in neuroendocrine secretion granules in submaxillary and parotid glands in patients with non-insulin dependent diabetes mellitus]. / Aumento de los gránulos de secreción neuroendócrina en glándulas submaxilares y parótidas en pacientes con diabetes mellitus no dependiente de insulina.

The amount of neuroendocrine granules in microgranular cells of salivary glands were investigated in necropsies of 20 non-insulin dependent diabetics (NIDDM) and in 20 non-diabetic subjects with Grimelius and Fontana-Masson stainings. Granules in serous acini, and intercalated ducts were observed in both groups; however, a significant higher number of granules and microgranular cells were observed in NIDDM subjects as compared with non-diabetics. Both parotid and submaxillary glands were significantly heavier in NIDDM than in the non-diabetic group. These granules may be related to immunoreactive glucagon which has been found in submaxillary glands of rodents and might play a role in the pathogenesis of NIDDM. Further investigations should be performed to clarify whether these cells are the site of glucagon synthesis and also clarify the pathogenesis of NIDDM.

[Obstructive hypertrophic myocardiopathy and coronary atherosclerosis]. / Miocardiopatía hipertrófica obstructiva y aterosclerosis coronaria.

The purpose of this study was to determine the coexistence of idiopathic hypertrophic cardiomyopathy (IHC) and atheromatous coronary artery disease. We studied forty six patients with IHC documented by complete clinical study and also by left heart catheterization. The diagnosis was considered established, when the patient had a significant left intraventricular pressure gradient (LIPG) and by angiographic and or echocardiographic demonstration of systolic anterior movement of the mitral valve and asymmetric septal hypertrophy. In 15 patients a selective coronary angiography was performed because ischemic myocardial disease was suspected. There were eight patients with significant atherosclerotic obstruction (greater than 75% narrowing). There was one vessel disease in 13%, two vessels in 37% and three vessels in 50% of the patients. The LIPG was 43 +/- 20 mmHg, the left ventricular and diastolic pressure (LVEDP) was 18 +/- 11 mmHg in patients with atheromatous disease and there was no significant difference with the patients with normal coronary arteries with LIPG 52 +/- 31 mmHg and LVEDP 21 +/- 9 mmHg. Our data demonstrate that ischemic heart disease in patients with idiopathic hypertrophic cardiomyopathy is related not only to increase of the cardiac mass and/or the ventricular wall stress, but in some of them atherosclerosis plays a role in its pathogenesis. Significant differences were found between the aged in both groups. In the patients who had coronary atherosclerosis the mean age was 54 years; on the other hand in the patients with normal coronary arteries the mean age was 44 years. This last fact could explain the high frequency of atherosclerosis in the older patients.

[Marfan syndrome and echocardiography]. / Síndrome de Marfan y ecocardiografía.

We report the echocardiographic features of nine patients with Marfan syndrome. Six men and three women. Average age: twenty nine years. Sixty six per cent had aneurysmatic enlargement of the aortic root. One hundred per cent of the cases had aortic insufficiency, enlargement of the left ventricular diameter, decrease of the ejection fraction, and decrease in circunferential shortening; mitral prolapse, (in 6) and signs of high pulmonary artery pressure (in 4 cases). Hemodynamic studies performed in 46 per cent of the patients correlated well with the echocardiographic features. Autopsy performed in the patients who died, corroborated the cardiovascular abnormalities. We conclude that the use of the echocardiogram is a useful non-invasive technique for the early evaluation of the cardiovascular features in the Marfan syndrome.

[Ebstein's anomaly with the Wolff-Parkinson-White syndrome]. / Anomalía de Ebstein con síndrome de Wolff-Parkinson-White.

Thirty-three patients were studied with Ebstein's anomaly, associated to Wolff-Parkinson-White syndrome with the purpose of analyze their electrophysiologic characteristics. In this patients the right preexcitation was before the activation of the right ventricle mass, overshadowing the manifestations of the right bundle branch block (usual in patients with Ebstein's anomaly without preexcitation). In conclusion the absence of manifestations of right bundle branch block in the presence of Ebstein's anomaly diagnosed by hemodynamic study or echocardiography let us think in the coexistence of the preexcitation and suggest the pertinent electrophysiologic study; as the association of supraventricular tachycardia in this group is very high (94%) most of them paroxysmal orthodromic tachycardia.