Biomedical subjects

Matthias P Heintzen

Publications and source records attributed to Matthias P Heintzen.

4 recordsLinked to original sources

PubMed2003

Effects of right coronary artery PTCA on variables of P-wave signal averaged electrocardiogram.

BACKGROUND: P-wave signal averaged ECG has been used to detect atrial late potentials that were found in paroxysmal atrial fibrillation. Ischemia is supposed to trigger ventricular late potentials, which indicate an elevated risk for ventricular tachycardia. Preexistent ventricular late potentials measured by ventricular signal averaged ECG is supposed to be eliminated by successful PTCA. METHODS: We examined the incidence of atrial late potentials in patients with a proximal stenosis of the right coronary artery and new onset of atrial fibrillation. Furthermore, we investigated the anti-ischemic effect of a successful percutaneous transluminal coronary angioplasty.(PTCA) of the right coronary artery. P-wave signal averaged ECG from 23 patients who had a PTCA of the right coronary artery (group A) were compared to age, sex, and disease-matched control subjects (group B) one day before, one day after, and one month after PTCA. RESULTS: A new appearance of paroxysmal atrial fibrillation was presented in eight patients before PTCA (group A1) of group A. Patients with a stenosis of the right coronary artery had a significantly higher incidence of supraventricular extrasystoles in a 24-hour-Holter ECG (131.1 +/- 45.4 vs 17.1 +/- 18.9, P < 0.0002). The duration of the filtered P wave was longer (124.8 +/- 11.9 vs 118.5 +/- 10.1 ms, P < 0.04) and the root mean square of the last 20 ms (RMS 20) was significantly lower in group A than in group B (2.87 +/- 1.09 vs 3.97 +/- 1.12 micro V, P < 0.01). A successful PTCA caused an increase in RMS 20 (2.87 +/- 1.11 vs 4.19 +/- 1.19 microV, P < 0.02) and a decrease in filtered P-wave duration (124.8 +/- 11.9 vs 118.4 +/- 10.4 ms, P < 0.04). Preexistent atrial late potentials were found among 15 patients before PTCA. After successful PTCA only 3 out of 15 patients were affected (P < 0.0004) after one day, as well as after one month. All patients with a history of atrial fibrillation did not suffer from an arrhythmic recurrence within the following six months after successful PTCA. CONCLUSION: A stenosis of the right coronary artery is associated with atrial late potentials. A successful PTCA of the right coronary artery eliminates preexistent atrial late potentials and may reduce the risk of atrial fibrillation.

Action Potentials↗

PubMed2002

Incidence and clinical outcome of iatrogenic femoral arteriovenous fistulas: implications for risk stratification and treatment.

OBJECTIVES: We sought to determine the incidence of arteriovenous fistulas (AVF), identify risk factors for AVF, and follow up the clinical outcome of femoral AVF. BACKGROUND: Arteriovenous fistulas are a potential harmful complication of cardiac catheterization. Incidence and clinical outcome of iatrogenic AVF are unknown so far, although important for risk stratification and treatment. METHODS: A total of 10,271 consecutive patients undergoing cardiac catheterization were followed up prospectively over a period of three years. Diagnosis of AVF was performed by duplex sonography. RESULTS: The incidence of AVF was 0.86% (n = 88). The following significant and independent risk factors for AVF were identified: high heparin dosage (odds ratio [OR]) = 2.88), coumadin therapy (OR = 2.34), puncture of the left groin (OR = 2.21), arterial hypertension (OR = 1.86), and female gender (OR = 1.84). Within 12 months 38% of all AVF closed spontaneously. No signs of cardiac volume overload or limb damage were observed in patients with persisting AVF. None of the risk factors for AVF influenced the incidence or the rate of AVF closure. Only intensified anticoagulation showed a tendency to extend AVF persistence. CONCLUSIONS: Almost 1% of patients undergoing cardiac catheterization acquire femoral AVF, for which patient- and procedure-related risk factors could be identified. One-third of iatrogenic AVF close spontaneously within one year. Cardiac volume overload and limb damage are highly unlikely with AVF persistence. Thus, a conservative management for at least one year seems to be justified.

Aged↗

PubMed2002

Conversion of recent-onset atrial fibrillation or flutter with ibutilide after amiodarone has failed.

OBJECTIVE: To evaluate whether ibutilide can convert atrial fibrillation or flutter in patients in whom amiodarone has failed. DESIGN AND SETTING: Clinical study in a university hospital intensive care unit (ICU). PATIENTS: Twenty-six patients were studied, in whom atrial fibrillation or flutter persisted for a maximum of 6 h at maximum. Patients were monitored continuously during the arrhythmia. Medical conversion was necessary due to symptomatic or hemodynamic causes. INTERVENTIONS: All patients initially received amiodarone (150 mg i.v.) and after 2 h of persistent arrhythmia ibutilide (1 mg or, without success and body weight > 70 kg, 2 mg i.v.). Before the administration of ibutilide 1 g magnesium was administered, and high normal levels of potassium serum levels were achieved (4.5-5.0 mmol/l). RESULTS. After amiodarone atrial flutter persisted in 73% and atrial fibrillation in 27% of patients. After ibutilide the QT interval was prolonged from 327 +/- 61 to 387 +/- 62 ms. The QTc interval increased from 456 +/-32 to 461 +/- 66 ms. Conversion to normal sinus rhythm was achieved in 22 of 27 of cases. Nonsustained torsade de pointes tachycardia was seen in three patients (11%). No patient showed sustained ventricular tachycardia. Patients with proarrhythmic effects were characterized by a decreased left ventricular function. CONCLUSIONS: In ICU patients ibutilide led to conversion to sinus rhythm in 81.5% of patients in whom amiodarone was unsuccessful. Nonsustained tachycardias were seen in 11%; sustained ventricular tachycardia was not seen. Ibutilide seems to be well suitable for conversion of recent onset atrial fibrillation or flutter and had no severe side effects in this study population.

Aged↗

PubMed2002

Debulking prior to stenting--a worthwhile effort?

The rationale of debulking prior to stenting is to improve acute and long-term results of complex lesion angioplasty by reduction of plaque burden and/or reduction of calcified material prior to stenting, thus, allowing subsequent optimized stent-implantation and expansion. There are several registries analyzing the effect of various debulking-strategies prior to stenting in groups of selected patients and in high-risk subgroups. The majority of these studies performed DCA prior to stenting. In summary, these studies showed a reduction in restenosis rates and need for reintervention at long-term follow-up. The total TLR-rate (PCI, CABG) during a mean follow-up of 6 to 14 months is reported to be 4 to 14%; the rate of restenosis is given as 7 to 14%. However, until now, no large scale randomised "debulking prior to stenting" versus "conventional stenting without debulking" study has been published in detail. Several studies suggest benefit for debulking prior to stenting in complex lesion subsets, e.g., total chronic occlusions, ostial lesions, bifurcation lesions and saphenous vein grafts, but as of now, no convincing strategy has evolved.

Angioplasty, Balloon, Coronary↗