Biomedical subjects

Marcus Hennersdorf

Publications and source records attributed to Marcus Hennersdorf.

9 recordsLinked to original sources

PubMed2006

Amiodarone prophylaxis for atrial fibrillation of high-risk patients after coronary bypass grafting: a prospective, double-blinded, placebo-controlled, randomized study.

AIMS: Atrial fibrillation (AF) occurs often in patients after coronary artery bypass grafting (CABG) and can result in increased morbidity and mortality. Previous studies using P-wave signal-averaged electrocardiogram (P-SAECG) have shown that patients with a longer filtered P-wave duration (FPD) have a high risk of AF after CABG. We have shown that patients with an FPD > or = 124 ms and a root-mean-square voltage of the last 20 ms of the P-wave 20 < or = 3.7 microV have an increased risk of AF after surgery. Accordingly, the aim of this study was to investigate whether or not prophylactic peri-operative administration of amiodarone could reduce the incidence of AF in this high-risk group undergoing CABG identified by P-SAECG. METHODS AND RESULTS: In this prospective, double-blinded, placebo-controlled, randomized study, 110 patients received either amiodarone (n = 55) or placebo (n = 55). During CABG, two patients of both groups died. Amiodarone was given as 600 mg oral single dose one day before and from days 2 through 7 after surgery. In addition, amiodarone was also administered intravenously during surgery in a 300-mg bolus for 1 h and as a total maintenance dose of 20 mg/kg weight over 24 h on the first day following surgery. The primary endpoint was the occurrence of AF after CABG. The secondary endpoint was the hospitalization length of stay after CABG. The baseline characteristics were similar in both treatment groups. The incidence of post-operative AF was significantly higher in the placebo group compared with the amiodarone group (85 vs. 34% of patients, P < 0.0001). The prophylactic therapy with amiodarone significantly reduced the intensive care (1.8 +/- 1.7 vs. 2.4 +/- 1.5 days, P = 0.001) and hospitalization length of stay (11.3 +/- 3.4 vs. 13.0 +/- 4.3 days, P = 0.03). In the amiodarone group, concentrations of amiodarone and desethylamiodarone differed significantly between patients with AF and sinus rhythm (amiodarone: 0.96 +/- 0.5 vs. 0.62 +/- 0.4 microg/mL, P = 0.02; desethylamiodarone: 0.65 +/- 0.2 vs. 0.48 +/- 0.1 microg/mL, P = 0.04). CONCLUSION: The incidence of post-operative AF among high-risk patients was significantly reduced by a prophylactic amiodarone treatment resulting in a shorter time of intensive care unit and hospital stay. Our data supports the prophylactic use of amiodarone in peri-operative period in patients at high risk for AF after CABG.

Aged↗

PubMed2006

HFE mutations in idiopathic dilated cardiomyopathy.

BACKGROUND AND PURPOSE: Dilated cardiomyopathy is a typical complication of hereditary hemochromatosis (HH). The present study investigated, whether mutations of the hemochromatosis (HFE) gene might be etiologic and disease-modifying factors in idiopathic dilated cardiomyopathy PATIENTS AND METHODS: Clinical and biochemical assessment and HFE gene analysis were perfomed in 46 patients with IDCM and 350 healthy controls. Cardiomyopathy was angiographically defined according to the criteria of the Collaborative Research Group of the European Human and Capital Mobility Project of Familial Dilated Cardiomyopathy. RESULTS: A higher prevalence of C282Y homozygosity was found among patients with IDCM compared to healthy subjects (4.3% vs. 0.6%; p < 0.02). A total of 6.5% of the patients with IDCM were either C282Y homozygotes or C282Y/H63D compound heterozygotes. The C282Y allele frequency was somewhat higher among patients with IDCM (8.7%) compared to healthy controls (5.4%; p < 0.2), whereas the H63D allele frequency was not increased. No significant differences of serum iron, ferritin or transferrin saturation, cardiac iron loading, NYHA classification, Lown's classification, the history of cardiopulmonary resuscitation, LVEDD (left ventricular end-diastolic diameter), EF (ejection fraction), LADD (left atrial end-diastolic diameter) and CI (cardiac index) were seen between HFE carriers and noncarriers. CONCLUSION: The present study indicates that it is worth screening patients with IDCM for iron parameters given the increased prevalence of disease-predisposing HFE constellations. It remains unclear, to what extent iron or immune-mediated processes contribute to the pathomechanism of IDCM.

Adult↗

PubMed2006

Prediction of atrial fibrillation after coronary artery bypass grafting: the role of chemoreflex-sensitivity and P wave signal averaged ECG.

Atrial fibrillation (AF) after coronary artery bypass grafting (CABG) results in a prolonged hospital stay associated with higher costs. In our study P wave triggered P wave signal averaged ECG and chemoreflex-sensitivity (CHRS) was performed on 101 consecutive patients with sinus rhythm before CABG in order to evaluate the utility of these methods to predict AF. A CHRS below 3.0 ms/mm Hg was predefined as a pathological CHRS. Postoperative AF was observed in 37 (37%) of 101 patients. Patients with AF were older (68.4+/-6.9 vs. 63.8+/-9.4 years, p<0.01), had a longer filtered P-wave duration (FPD) (133.6+/-10.2 vs. 123.6+/-14.9 ms, p<0.0001), a lower root mean square voltage of the last 20 ms of the P wave (RMS 20) (2.86+/-0.88 vs. 5.10+/-2.73 microV, p<0.0001) and a significantly lower CHRS (3.32+/-1.83 vs. 4.17+/-2.19 ms/mm Hg, p<0.05). A cut-off point (COP) of FPD> or =124 ms and RMS 20< or =3.7 microV achieved a specificity of 75%, a sensitivity of 78%, a negative predictive value of 86%, a positive predictive value of 64% and an accuracy of 76% for prediction of AF. The predictive power was lower for a pathological CHRS which achieved a specificity of 63%, a sensitivity of 60%, a negative predictive value of 73%, a positive predictive value of 48% and an accuracy of 61%. A stepwise logistic regression analysis of all preoperative variables identified COP (odds ratio 8.21; 95% CI, 2.02-33.37, p<0.003) as independent predictor. Patients with postoperative AF stayed longer in the intensive care unit (2.9+/-1.7 vs. 1.3+/-0.5 days, p<0.0001) and in hospital (13.5+/-4.3 vs. 11.4+/-1.1 days, p<0.0004). The results of our study show that the risk for AF after CABG could preoperatively be predicted with P wave signal averaged ECG and an analysis of CHRS. The predictive power of the COP could be used for a preoperative risk stratification and a corresponding prophylactic therapy in order to reduce costs.

Aged↗

PubMed2006

Citrate plasma levels in patients under regional anticoagulation in continuous venovenous hemofiltration.

BACKGROUND: Different methods of regional anticoagulation using citrate in continuous hemofiltration have been described. To date, only such surrogate parameters as pH, anion gap, total calcium concentration, or total calcium-ionized calcium ratio have been proposed to reflect increased plasma citrate levels and thus risk for side effects. However, none of these parameters has been correlated with plasma citrate levels in critically ill patients. METHODS: Sixteen patients were treated with continuous venovenous hemofiltration (CVVH) and citrate anticoagulation for a mean of 13 +/- 9 days. Citrate levels were measured every other day, and correlations were calculated with the mentioned parameters. RESULTS: Steady-state citrate levels on treatment day 3 were 16.39 +/- 15.77 mg/dL (range, 2.63 to 73.49 mg/dL [853 +/- 821 micromol/L; range, 137 to 3825 micromol/L]). The highest correlation was found between citrate plasma level and total calcium-ionized calcium ratio (R = 0.85; P < 0.001). pH (R = -0.15) and anion gap (R = 0.36) were not helpful in estimating citrate plasma levels in patients treated with citrate-CVVH. CONCLUSION: Calculating total calcium-ionized calcium ratio is a simple tool that correlates best with citrate plasma levels. We recommend close monitoring of this parameter in all patients administered high doses of citrate as part of regional anticoagulation protocols.

Acute Kidney Injury↗

PubMed2005

Altered blood rheology in obstructive sleep apnea as a mediator of cardiovascular risk.

BACKGROUND: Cardiovascular complications are common in patients with obstructive sleep apnea (OSA). Blood rheology is a major determent of coagulation and an established risk factor for cardiovascular events. Since nocturnal hypoxemia could influence parameters of blood rheology, we hypothesized that OSA alters blood rheology independent of other cardiovascular risk factors. METHODS: One hundred and ten consecutive patients admitted to the sleep laboratory were included. The association of plasma fibrinogen and viscosity (as parameters of blood rheology) with OSA was evaluated. RESULTS: One hundred and ten patients aged 61.4+/-10.1 years (body mass index 28.4+/-4.1 kg/m2) were included. OSA was confirmed in 63 patients (57.2%) with an apnea-hypopnea index (AHI) of 28.7+/-14.9 events/hour. Patients with OSA showed higher levels of plasma viscosity (1.36+/-0.09 vs. 1.31+/-0.08 mPas, p=0.005). Nevertheless, hypertensive apneics have even higher levels of plasma viscosity than nonapneics (1.38+/-0.091 vs. 1.32+/-0.028 mPas, p=0.018). Similar results were found in patients with coronary artery disease, where OSA was associated with elevated plasma viscosity (1.36+/-0.076 vs. 1.31+/-0.081 mPas, p=0.007). Plasma fibrinogen was correlated with nocturnal minimal oxygen saturation (r=-0275, p=0.0036) and AHI (r=0.297, p=0.001). OSA was associated with higher plasma fibrinogen (353+/-83 vs. 317+/-62 mg/dl, p=0.015). These differences persist with control for cardiovascular risk factors. CONCLUSIONS: Patients with OSA have elevated morning fibrinogen levels and a higher plasma viscosity, which correlate positively with indices of sleep apnea severity. These changes in blood rheology are independent of cardiovascular risk factors, and therefore, might be specific mechanisms of OSA. This supports the pathophysiological concept that sleep apnea is a cardiovascular risk factor.

Adult↗

PubMed2005

P wave signal averaged ECG and chemoreflexsensitivity in paroxysmal atrial fibrillation.

Detailed analysis of the QRS-complex and autonomic dysfunction can identify patients at risk to suffer from ventricular arrhythmias. To determine whether patients at risk for paroxysmal atrial fibrillation (PAF) could be identified while in sinus rhythm, a P wave triggered signal averaged ECG and an analysis of the autonomic function by chemoreflexsensitivity (CHRS) were examined. The ratio between the difference of RR intervals in the ECG and the venous partial pressure of oxygen before and after 5-min oxygen inhalation was measured for the determination of CHRS. We examined 224 patients (group A) who suffered from PAF, 250 patients (group B) without arrhythmic history and 30 young volunteers (group C). The filtered P wave duration (FPD) was significantly longer in group A than in group B (140.9+/-21.0 vs. 118.2+/-9.4 ms, p<0.0001) or C (105.2+/-14.1 ms, p<0.0001) while the root mean square voltage of the last 20 ms of the P wave (RMS 20) was significantly lower in group A than in group B (2.68+/-1.12 vs. 4.06+/-1.57 microV, p<0.0001) or C (3.97+/-1.36 microV, p<0.0001). Atrial late potentials (ALP) were defined as a FPD>120 ms and a RMS 20< or =3.5 microV. ALP could identify patients of group A with a specificity of 78% and a sensitivity of 83%. Patients with PAF (2.32+/-1.15 ms/mm Hg) showed a significantly lower CHRS than group B (4.14+/-1.58 ms/mm Hg, p<0.0001) or group C (4.98+/-1.51 ms/mm Hg, p<0.0001). The sensitivity for the presence of atrial fibrillation was 71% for a CHRS below 3.0 ms/mm Hg with a specificity of 70%. A combination of both methods showed a specificity of 85% and a sensitivity of 65% when ALP and pathological CHRS were present. The results of our study suggest that risk of atrial fibrillation could be detected by P wave signal averaged ECG and CHRS. An analysis of CHRS seems to be an appropriate method to demonstrate a neurovegetative imbalance, which might be one possible trigger mechanism.

Adolescent↗

PubMed2005

Prediction of the recurrence of atrial fibrillation after successful cardioversion with P wave signal-averaged ECG.

BACKGROUND: The recurrence of atrial fibrillation (AF) was often observed after cardioversion. METHODS: In our study, a P wave triggered P wave signal-averaged ECG (P-SAECG) was performed on 118 consecutive patients 1 day after successful electrical cardioversion in order to evaluate the utility of this method to predict AF after cardioversion. We measured the filtered P wave duration (FPD) and the root mean square voltage of the last 20 ms of the P wave (RMS 20). RESULTS: During a 1-year follow-up, a recurrence was observed in 57 patients (48%). Patients with recurrence of AF had a larger left atrial size (41.9 +/- 4.0 vs 39.3 +/- 3.1 mm, P < 0.0003), a longer FPD (139.6 +/- 16.0 vs 118.2 +/- 14.1 ms, P < 0.0001), and a lower RMS 20 (2.57 +/- 0.77 vs 3.90 +/- 0.99 microV, P < 0.0001). A cutoff point (COP) of FPD > or =126 ms and RMS 20 < or =3.1 microV could predict AF with a specificity of 77%, a sensitivity of 72%, a positive value of 75%, a negative predictive value of 75%, and an accuracy of 75%. A stepwise logistic regression analysis of variables identified COP (odds ratio 9.97; 95% CI, 4.10-24.24, P < 0.0001) as an independent predictor for recurrence. CONCLUSIONS: We conclude that the probability of recurrence of AF after cardioversion could be predicted by P-SAECG. This method seems to be appropriate to demonstrate a delayed atrial conduction that might be a possible risk factor of reinitiation of AF.

Atrial Fibrillation↗

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

A seropneumothorax?

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Diagnosis, Differential↗