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Biomedical subjects

N Treese

Publications and source records attributed to N Treese.

At least 91 records · Page 5Linked to original sources
PubMed1985

Prognostic significance of repetitive ventricular response in chronic coronary artery disease.

A prospective study was conducted in 267 patients with angiographically defined coronary artery disease without documented ventricular tachycardia to determine the prognostic significance of repetitive ventricular response (RVR) after programmed electrical stimulation (PES). The patients were classified inducible if RVR with 3 or more echo beats (RVR greater than or equal to 3) could be induced. 89 patients without previous myocardial infarction (MI), 61 survivors of MI occurring between 6 weeks and 3 months before and 117 patients who had survived longer than 3 months after MI were studied. A standardized stimulation protocol with single (S1S2) and double (S1S2S3) extrastimuli during ventricular drive at a cycle length of 600, 500 and 430 ms with a current strength below 5 mA at the right ventricular apex was employed. Ventricular responses with 3 to 5 echo beats (RVR3-5) and with 6 and more echo beats (RVR greater than or equal to 6) were distinguished. In 68 (25%) patients RVR3-5 and in 38 (14%) patients RVR greater than or equal to 6 was observed; in 11 patients with RVR greater than or equal to 6 sustained VT was initiated which was monomorphic in 5 of them. The occurrence of RVR greater than or equal to 6 was related to the time interval to prior MI and most frequently found within 3 months of MI. A higher incidence of RVR greater than or equal to 6 was observed in more advanced CAD, although the angiographic findings were unable to predict the results of PES. During a mean follow up of 20 months 11 patients died, 8 suddenly, 3 in cardiac failure. Those who died had more extensive CAD, RVR greater than or equal to 3 was found in 4 of them and nonsustained VT in one. The sensitivity of RVR greater than or equal to 3 as a predictor of sudden death (SD) was 36% and the specifity 60%. The predictive value of inducibility of RVR greater than or equal to 3 as indicator of SD was 4% and the predictive value of noninducibility was 98%. It is concluded that in patients with chronic CAD without spontaneous VT, RVR with 3 more echo beats does not identify a predisposition to die suddenly.

Adult↗
PubMed1985

Effect of intravenous flecainide on atrial vulnerability in man.

Sixteen patients were investigated by means of programmed atrial stimulation at 2 different driving rates: 100/min and 120/min. All patients had an increased atrial vulnerability at both driving rates. After the administration of intravenous flecainide (1 mg/kg bodyweight as a bolus, followed by the same amount infused over a period of 20 minutes), the increased vulnerability was abolished in 11 and 9 patients, respectively. In the remaining patients the rate of induced atrial tachyarrhythmia decreased. These findings correlate with a significant prolongation of the effective refractory period of the right atrium and a corresponding significant shortening of its relative refractory period. It is concluded that flecainide may be effective in the treatment of atrial arrhythmias in humans.

Adolescent↗
PubMed1984

Atrioventricular dissociation detected by suprasternal M-mode echocardiography: a clue to the diagnosis of ventricular tachycardia.

Twenty-two patients were studied by suprasternal M-mode echocardiography during ventricular tachycardia (VT). Adequate echocardiograms were obtained from 19 patients. Thirteen patients showed atrioventricular (AV) dissociation and 6 patients a ventriculoatrial contraction pattern according to the left atrial (LA) contraction obtained from the suprasternal notch. In 1 of these 6 patients, a 2:1 block retrograde was found by echocardiography. In another patient, an intermittent block occurred in the retrograde direction. In 4 patients, a constant relation between the QRS complex and LA contraction soon after the beginning of the QRS complex was seen, demonstrating a 1:1 ventriculoatrial conduction. According to the LA contraction obtained from the suprasternal echocardiogram, 13 patients showed AV dissociation and 6 patients a retrograde conduction to the LA. From the analysis of the 12-lead standard electrocardiogram obtained simultaneously during VT, AV dissociation could be recognized in only 3 patients. Thus, AV dissociation during VT is more easily diagnosed with suprasternal M-mode echocardiography than with the standard electrocardiogram.

Adult↗
PubMed1984

Long-term antiarrhythmic therapy with flecainide.

The antiarrhythmic efficacy and safety of oral flecainide were assessed during a controlled 2-week and a subsequent 48-week long-term trial. Fifteen patients with frequent (more than 30 per hour) and complex ventricular arrhythmias (Lown grade IVA or IVB) who had been resistant or intolerant to 2 or more antiarrhythmic agents, were included in the study. Antiarrhythmic efficacy was controlled by 24-hour Holter monitoring at 2, 12, 24 and 48 weeks. The administration of 100 to 200 mg flecainide twice daily resulted in more than 90% suppression of VPCs and of complex ventricular arrhythmias in 14 of 15 patients. The minimum effective therapeutic dose could be titrated in 9 of 14 patients to 100 mg twice daily, in 3 of 14 patients to 150 mg twice daily and in 2 of 14 patients to 200 mg twice daily. During this therapy and a mean plasma concentration of 886 +/- 103 ng/ml, PQ and QRS duration, as well as QTc time and JTc interval were not significantly changed. Side effects (gastrointestinal complaints, nausea, obstipation, dizziness, visual disturbances, headache and impaired potency) were seen in 5 of 14 patients after 12 weeks, in 3 of 4 patients after 24 weeks and in only 2 of 14 patients after 48 weeks. Side effects were described as mild and tolerable and did not limit flecainide therapy except in 1 patient, who had discontinued therapy with flecainide after 3 days because of intense gastrointestinal symptoms. In conclusion, flecainide is highly effective and well tolerated in the long-term treatment of serious ventricular arrhythmias.

Adult↗
PubMed1984

Significance of ventricular arrhythmias in idiopathic dilated cardiomyopathy.

The incidence and prognostic significance of ventricular arrhythmias identified by 24-hour ambulatory electrocardiography (Holter) was prospectively assessed in 74 patients with idiopathic dilated cardiomyopathy (IDC). The criteria for diagnosis of IDC were based on clinical and cardiac catheterization findings. Holter monitoring was performed at the time of entry into the study. Patients were followed for 2 to 21 months (mean 11 +/- 3). Frequent ventricular premature complexes (VPCs) (greater than 1,000/24 hours) were seen in 35%, and complex VPCs (Lown grade III and IV) in 87% of the patients. Forty-nine percent of the patients had nonsustained ventricular tachycardia (VT) consisting of 3 to 32 beats with rates from 110 to 230 beats/min, and 20% had ventricular pairs. No correlation was found between clinical symptoms or the degree of left ventricular (LV) impairment and the number of ventricular pairs or episodes of VT. During follow-up, 19 patients died, 7 from congestive heart failure (CHF) and 12 suddenly. Patients who died suddenly had significantly more episodes of VT, ventricular pairs or total VPCs (p less than 0.01 each) compared with survivors and those who died from CHF. No significant differences were found between patients who died from CHF or suddenly with respect to LV end-diastolic pressure, LV end-diastolic volume index, LV ejection fraction (EF) and cardiac index. A linear stepwise discriminant function analysis using hemodynamic (LVEF and cardiac index) and arrhythmic (number of VT episodes and ventricular pairs) variables resulted in a meaningful separation between survivors and patients who died from CHF or suddenly.(ABSTRACT TRUNCATED AT 250 WORDS)

Arrhythmias, Cardiac↗
PubMed1984

[Functional autonomic blockade in the diagnosis of functional sinus node disorders].

The influence of the autonomic nervous system on sinus node automatism was assessed in 61 patients with suspect sinus node dysfunction. Cardiac frequency and corrected sinus node recovery time (CSNRT) were determined before and after functional autonomic blockade with intravenously administered propranolol (0,2 mg/kg) and atropine (0,04 mg/kg). A pathologic CSNRT was found in 59% of patients before and in 54% after autonomic blockade. In 44% pathologic CSNRT occurred during both conditions. In these patients intrinsic sinus node disease can be assumed. In 15% of patients an initially pathologic CSNRT became normal after blockade. In these patients sinus node dysfunction is caused by autonomic dysregulation. In 10% of patients pathologic CSNRT was seen for the first time after blockade. In such patients an altered autonomic balance seems to camouflage the primary intrinsic sinus node disease. Abnormal intrinsic cardiac frequency (cardiac frequency after autonomic blockade) was observed in pathologic prolongation of CSNRT after blockade, however not in normal CSNRT. On the other hand only 39% of patients with prolonged CSNRT after blockade had at the same time an abnormal intrinsic cardiac frequency. Autonomic blockade improves the diagnosis of the sick sinus node syndrome. Demonstration of abnormal intrinsic cardiac frequency is highly specific of intrinsic sinus node disease. Normal intrinsic cardiac frequency does, however, not exclude intrinsic sinus node disease.

Adolescent↗
PubMed1984

Incidence and clinical significance of repetitive ventricular response in patients without identifiable organic heart disease.

We determined the incidence of repetitive ventricular response (RVR) after programmed electrical stimulation and the incidence of spontaneous ventricular arrhythmias during 24 hr Holter monitoring in 38 patients in whom extensive non-invasive and invasive diagnostic tests had excluded abnormalities suggestive of organic heart disease. A standardized stimulation protocol with single (S1S2) and double (S1S2S3) extrastimuli during ventricular drive at cycle lengths of 600, 500 and 430 msec with a current strength below 5 mA at the right ventricular apex was employed. RVR occurred in 20 patients (58%) after S1S2 and in 30 patients (79%) after S1S2S3 stimulation. Eighteen patients (47%) showed RVR with 2 echo beats and 1 patient had 3 echo beats. RVR was due to bundle branch reentry (BBR) in 20 patients independent of the mode of stimulation. RVR due to intraventricular reentry (IVR) was found in 17 patients (47%) only after S1S2S3 stimulation. The incidence of both BBR and IVR was influenced by the basic ventricular driving rate, decreasing with shorter basic cycle lengths. 17 patients had no ventricular premature depolarizations (VPDs), 12 patients had uniform, 4 multiform (Lown III), 2 consecutive (Lown IVA) VPDs, and 1 patient had parasystolic rhythm. There was no relation to the incidence of repetitive ventricular response. We conclude that in patients without identifiable organic heart disease RVR with more than 2 consecutive beats is rarely found if single and double extrastimuli are employed during ventricular drive. Both bundle branch and intraventricular reentry with one or two echo beats are a common finding in this population without relation to the incidence of spontaneous ventricular arrhythmias.

Adult↗
PubMed1984

[Repetitive ventricular response by programmed electrostimulation of the heart: frequency and clinical significance].

The induction of a repetitive ventricular response (RVR) by programmed electrical stimulation (PES) in patients with malignant ventricular arrhythmias such as ventricular tachycardia or ventricular fibrillation is associated with poor prognosis. However, the incidence and clinical significance of RVR in patients with normal hearts and in those with coronary artery disease (CAD) who do not have a history of malignant ventricular arrhythmias are unknown. In this paper, we present our views on the clinical value of PES in those patients. The incidence of RVR in patients without evidence of heart disease remains controversial. The possible reasons for the disparities between studies are due to differences in the study populations and stimulation protocols used. In 38 patients with normal hearts proven by left ventricular and coronary angiography no patient had three or more ventricular depolarizations in response to PES with single and double premature stimuli. The same stimulation protocol was used in 136 patients with coronary artery disease. The incidence of RVR greater than or equal to 3 (three or more ventricular depolarizations in response to PES) was related to the time interval to prior acute myocardial infarction and to the degree but not to the extent of left ventricular wall motion abnormalities. The relationship between spontaneous ventricular arrhythmias and those induced by PES was compared in 267 patients. Although there was some correlation between absence or presence of both types of arrhythmias, the presence of RVR greater than or equal to 3 did not predict precisely the presence of high grade ventricular arrhythmias during Holter-monitoring. The prognostic significance of RVR greater than or equal to 3 in patients with chronic stable coronary artery disease remains to be determined. However in patients with recent acute myocardial infarction it has been found that subjects at risk of sudden death (SD) can be identified by PES. We feel that until the prognostic significance of RVR is better defined its use as a basis for guiding antiarrhythmic therapy is not warranted.

Arrhythmias, Cardiac↗
PubMed1984

[Successful transvenous electric ablation of the AV conduction system in therapy-refractory atrial flutter].

The technique of closed-chest ablation of the atrioventricular (AV) conduction system was used in 3 patients (53-62 years of age) with atrial flutter not responding to medical management. A persistent third-degree AV block was induced in all patients. Moderate increases in CK and CKMB enzymes but not in Tc-pyrophosphate uptake were observed in these patients. 5 days after the procedure a permanent pacemaker was implanted in each case. We conclude that closed-chest ablation of the AV conduction system is a safe and efficient procedure in selected patients with drug-resistant supraventricular arrhythmias.

Adult↗
PubMed1983

Diagnosis of increased pulmonary blood flow by suprasternal M-mode echocardiography in atrial septal defect.

The right pulmonary artery (PA) was quantitatively assessed by suprasternal M-mode echocardiography in 25 patients in whom an atrial septal defect (ASD) was suspected clinically. In 10 patients an ASD was excluded (Group 1) and in 15 it was confirmed (Group 2). The smallest diameter of the right PA at end-diastole in Group 1 was 8.8 +/- 1.5 mm/m2 body surface area and in Group 2 14.8 +/- 3.6 mm/m2 (p less than 0.001). The greatest diameter of the right PA during systole was also much smaller in Group 1 (11.3 +/- 1.2 mm/m2) than in Group 2 (17.7 +/- 3.5 mm/m2) (p less than 0.001). The absolute and percent systolic expansion of the right PA did not differ in the 2 groups (2.7 +/- 0.5 mm [29.1 +/- 10.8%] in Group 1 and 2.9 +/- 0.8 mm [20.8 +/- 9.8%] in Group 2). No correlation was found between measured and derived echocardiographic variables of the right PA and the magnitude of the left-to-right shunt. Patients in Group 2, who had an additional pressure elevation in the PA, showed, on average, a larger right PA and a smaller percent systolic expansion. The study demonstrates characteristic alterations in the wall motion pattern of the right PA in patients with ASD, indicating increased pulmonary blood flow.

Adolescent↗
PubMed1983

Effect of intravenous flecainide on atrial vulnerability in man.

Sixteen patients were investigated by means of programmed atrial stimulation at two different driving rates: 100 and 120/min. All patients had an increased atrial vulnerability at both driving rates. After intravenous flecainide application (1 mg/kg body weight as a bolus followed by the same amount given by infusion over a period of 20 min) the increased vulnerability was abolished in 11 and 9 patients respectively. In the remaining patients the rate of induced atrial tachyarrhythmia decreased. These findings correlate with a significant prolongation of the effective refractory period of the right atrium and a significant shortening of the relative refractory period of the right atrium. It is concluded that flecainide may be effective in the treatment of atrial arrhythmias in man.

Adolescent↗
PubMed1983

Influence of digoxin on sinus node function after pharmacologic autonomic blockade.

The effect of iv digoxin on normal sinus node function was studied after pharmacologic autonomic blockade (AB) in ten patients. Sinus cycle length (SCL), sinus node recovery time (SNRT) and sinoatrial conduction time (SACT) were determined before and after AB with propranolol (0.2 mg/kg body weight) and atropine sulfate (0.04 mg/kg body weight) iv, and 15 min, 30 min, and 45 min after 1 mg iv digoxin. AB resulted in a significant decrease (P less than 0.01) in SCL (916 +/- 158 to 716 +/- 120 ms), in SNRT (1,229 +/- 221 to 871 +/- 190 ms), and in SACT (79 +/- 34 to 44 +/- 10 ms). Fifteen minutes after iv digoxin there was no significant change observed in SCL (716 +/- 120 to 708 +/- 92 ms), in SNRT (871 +/- 190 to 864 +/- 148 ms), or in SACT (44 +/- 10 to 46 +/- 15 ms). Similar results were obtained 30 min after digoxin administration. It is concluded that a single therapeutic dose of digoxin has no direct effect on electrophysiologic parameters of normal intrinsic sinus node function.

Adult↗
PubMed1983

[Closed intracardiac cardioversion in therapy resistant atrial flutter].

Cardiac frequency could not be lowered in a 62-year-old patient with atrial flutter and 2:1 conduction. Using an electrode catheter positioned in the His bundle area an electric current of 80 Ws was effected. A third-degree atrioventricular block developed which regressed after 6 hours. The electrophysiologic assessment after one week showed a marked diminution of AV node conduction capacity.

Acetyldigoxins↗
PubMed1983

[Arrhythmias in subjects with a healthy heart].

Of 350 patients who had extensive non-invasive and invasive cardiological diagnostic tests, 56 had completely normal results. 24-hour ECG monitoring of the latter revealed the following ventricular arrhythmias-ventricular extrasystoles (VES): 36% without, 23% with rare ones (less than 30/h), 5.4% with more than 30/h, 25% with polytopic VES, 7.1% with paired VES and 3.6% with ventricular tachycardia. There was no preferential VES pattern. Mean duration of VES was 0.15 s. There were no VES with a prematurity index of less than 1. Extending ECG monitoring to 96 hours (10 persons without heart disease) did not reveal any more significant VES, but registering for less than 24 hours definitely underestimated the frequency of VES in persons without heart disease. In those without angiographic evidence of heart disease 36% had complex and 5.4% frequent VES. Complex arrhythmias, however, are rare in the individual subject and generally not accompanied by frequent VES. Frequent complex arrhythmias or both frequent and complex arrhythmias, as well as VES with a prematurity index less than 1, are suggestive of organic heart disease.

Adult↗
PubMed1983

[Incidence and clinical significance of ventricular arrhythmias in dilated cardiomyopathy].

The diagnosis of dilated (congestive) cardiomyopathy was made in 75 patients on the basis of clinical, ECG, echo and angiographic-haemodynamic findings. Ambulatory 24-hour monitoring was undertaken in all patients. Nearly all of them (93%) had ventricular extrasystoles (VES), 35% more often than 1000/24 h. In 15% VES occurred in pairs, in 44% as ventricular tachycardia. In general, frequent VES (greater than 30/h) also came in pairs and/or as ventricular tachycardia. On the other hand, not all patients with such complex arrhythmias also had frequent VES. In about 70% of all patients with ventricular tachycardia such episodes were registered repeatedly, in more than 40% more than five tachycardia episodes per 24 hours. In the majority of patients the tachycardia consisted of three (33%), four (12%) or five (18%) consecutive ventricular complexes. All episodes of ventricular tachycardia ended spontaneously and were clinically largely silent. Apparently there was no clinically relevant correlation between frequency and severity of the arrhythmia, on the one hand, and extent of abnormal ventricular function, on the other. These findings indicate that frequent and complex ventricular arrhythmias are a characteristic feature of dilated (congestive) cardiomyopathy. If they occur in heart disease of seemingly unknown aetiology, dilated cardiomyopathy should be suspected. Preliminary findings of long-term observation indicate that patients with frequent ventricular tachycardias have a higher risk of sudden death.

Adolescent↗