The diagnostic accuracy of truncated cardiovascular MR protocols for detecting non-ischemic cardiomyopathies.

Cardiovascular magnetic resonance imaging is one of the most important diagnostic modalities in the evaluation of cardiomyopathies. However, significant limitations are the complex and time-consuming workflows and the need of contrast agents. The aim of this multi-center retrospective study was to assess workflows and diagnostic value of a short, contrast agent-free cardiac magnetic resonance protocol. 160 patients from Heidelberg, Germany and 119 patients from Montreal, Canada with suspected cardiomyopathy and 20 healthy volunteers have been enrolled. Scans were performed at a 1.5Tesla or 3Tesla scanner in Heidelberg and at a 3Tesla scanner in Montreal. We used single-slice T1 map only. A stepwise analysis of images has been performed. The possible differential diagnosis after each step has been defined. T1-values and color-encoded T1 maps significantly contributed to the differential diagnosis in 54% of the cases (161/299); the final diagnosis has been done without late gadolinium enhancement images in 83% of healthy individuals, in 99% of patients with dilated cardiomyopathy, in 93% of amyloidosis patients, in 94% of patients with hypertrophic cardiomyopathy and in 85% of patients with hypertensive heart disease, respectively. Comparing the scan time with (48 ± 7 min) vs. without contrast agent (23 ± 5 min), significant time saving could be reached by the short protocol. Subgroup analysis showed the most additional diagnostic value of T1 maps in amyloidosis and hypertrophic cardiomyopathy or in confirmation of normal findings. In patients with unclear left ventricular hypertrophy, a short, non-contrast protocol can be used for diagnostic decision-making, if the quality of the T1 map is diagnostic, even if only one slice is available.

Left ventricular untwisting in athlete's heart: key role in early diastolic filling?

Untwisting contributes to left ventricular filling through suction generation. We sought to investigate diastolic function and untwisting dynamics in different forms of left ventricular hypertrophy: in athlete's heart and hypertrophic cardiomyopathy. Elite athletes in kayaking, canoeing and rowing (n=28), patients with hypertrophic cardiomyopathy (HCM, n=15) and healthy sedentary volunteers (n=13) were compared. Left ventricular volumes, wall thickness-to-volume ratio were assessed by cardiac MRI. Following conventional and tissue Doppler measurements, untwist and untwist rate were determined by speckle tracking echocardiography. Wall thickness-to-volume ratio describing remodelling was significantly higher in HCM, but similar in athletes and controls (athlete vs. HCM vs. control: 0.107±0.019 vs. 0.271±0.091 vs. 0.104±0.012 mm×m²/ml, mean±SD, p<0.001). Mitral lateral annulus e' velocity referred to diastolic dysfunction in HCM (15.3±3.6 vs. 7.9±3.3 vs. 15.0±3.0 cm/s, p<0.01). At time point of mitral valve opening, untwist and untwist rate were significantly different: the highest values were measured in athletes, while the lowest were found in HCM (untwist: 51.3±19.1 vs. 11.6±10.4 vs. 35.9±16.3%; untwist rate: -32.5±13.0 vs. -10.6±10.8 vs. -23.0±7.7°/s, p<0.05). Untwisting correlated with E/A, e' and E/e'. Athlete's heart is characterized by increased untwist and untwist rate, which can aid diastolic function. Evaluation of untwisting dynamics may help to distinguish pathological hypertrophy.

[Biatrial pacing--new possibility in the non-pharmacologic treatment of drug-resistant paroxysmal atrial fibrillation]. / Biatrialis ingerlés--a gyógyszerrezisztens paroxizmális pitvarfibrilláció nonfarmakológiás kezelésének újabb lehetósége.

Biatrial pacing seems to be a possible non-pharmacological therapeutic choice in the prevention of drug-refractory, paroxysmal atrial fibrillation. Biatrial pacing using standard right atrial and coronary sinus left atrial pacing shows an antiarrhythmic effect, which mechanism is not well understood. Biatrial pacemaker was implanted in three patients suffering from drug refractory, symptomatic paroxysmal atrial fibrillation (lone and nonvalvular in 2 and in one case, respectively). Interatrial conduction disturbance (P > 120 ms) was found in three case. Bradycardia dependent arrhythmia development was not observed. Left atrial and right atrial premature beats dominated in 2 and in one case, respectively. P-wave duration was decreased by biatrial pacing in every patients. Atrial fibrillation has not been detected in two patients 1 day and 4 weeks after pacemaker implantation (follow up period: 9 and 5 months), however antiarrhythmic drugs has been withdrawn. In the number of left atrial premature beats a marked decrease was observed. Neither biatrial nor standard right atrial pacing nor combined medical and atrial pacing antiarrhythmic therapy were proven to be effective. In Hungary we were the first to implant and apply effectively biatrial pacemaker in the prevention of paroxysmal drug-refractory atrial fibrillation. However better identification the responding patients subgroup with atrial fibrillation is needed.

[Biventicular pacing in patients with severe heart failure]. / Súlyos szívelégtelenség kezelése biventricularis ingerléssel.

According to initial clinical results biventricular pacing seems to be effective in the treatment of patients suffering from drug refractory severe heart failure combined with intraventricular conduction disturbance. Biventricular cardioverter defibrillators and biventricular pacemakers were implanted in patients suffering from drug refractory severe heart failure in 3 and in 2 cases, respectively (follow up > 6 months). NYHA III-IV functional class, low left ventricular ejection fraction (23.2 +/- 5.4%), wide QRS (> 150 ms) with left bundle branch block and lateral dyssynchrony were present in each case. The left ventricle was enlarged in each patient (end-diastolic/end-systolic diameter: 78.6 +/- 9.2/66.2 +/- 8.1 mm). The indications of cardioverter defibrillator implantations were both sustained ventricular tachycardia and ventricular fibrillation, nonsustained ventricular tachycardia combined with syncope in 2 and in 1 case, respectively. The duration of QRS decreased (190 +/- 36 vs. 134 +/- 17 ms, p = 0.012) and wall movement disorder disappeared. At the last follow up every patients were in NYHA II functional class and a decrease in left ventricular diameter could be observed (end-diastolic: 72 +/- 10.4 mm, p = 0.07; end-systolic: 62 +/- 10 mm, p = 0.09). During the follow up period (7.3 +/- 1.7 months) 18 episodes of ventricular arrhythmias could be detected in the same patient. Biventricular pacemakers and cardioverter defibrillators were implanted and applied successfully in the treatment of congestive heart failure for the first time in Hungary. The effect of biventricular pacing on morbidity and mortality, the cost-effectiveness, the exact indication and the combined use with cardioverter defibrillator have yet to be proven in future randomized trials.

[Multichamber pacing--a new non-pharmacologic method for the treatment of severe heart failure]. / Többüregú ingerlés--a súlyos szívelégtelenség kezelésének új nonfarmakológiás módszere.

According to initial clinical results biventricular pacing seems to be effective in the treatment of patients suffering from drug refractory severe heart failure combined with intraventricular conduction disturbance. Biventricular cardioverter defibrillators and biventricular pacemakers were implanted in patients suffering from drug refractory severe heart failure in 10 and in 15 cases, respectively. NYHA III-IV functional class, low left ventricular ejection fraction (24.2 +/- 6%), wide QRS (> 150 ms) with left bundle branch block and lateral dyssynchrony were present in each case. The left ventricle was enlarged in each patient (endodiastolic/endsystolic diameter: 78.6 +/- 9.2/68.2 +/- 8.3). The indications of cardioverter defibrillator implantations were both sustained ventricular tachycardia and ventricular fibrillation, nonsustained ventricular tachycardia combined with syncope in 7 and in 3 case, respectively. The duration of QRS decreased (187 +/- 32 vs. 136 +/- 19 ms, p = 0.012) and wall movement disorder disappeared. At the last follow up every patients were in NYHA II functional class and a decrease in left ventricular diameter could be observed (endodiastolic: 70.3 +/- 9.1 mm, p = 0.04; endosystolic: 61.9 +/- 8.8 mm, p = 0.04). During the follow up period (8.8 +/- 5.1 months) 18 episodes of ventricular arrhythmias were detected in the same patient, 2 patients died (1 arrhythmia death, 1 sudden cardiac death). Biventricular pacemakers and cardioverter defibrillators were implanted and applied successfully in the treatment of congestive heart failure for the first time in Hungary.

Bosentan the mixed endothelin-A- and -B-receptor antagonist suppresses intrapericardial endothelin-1-induced ventricular arrhythmias.

In earlier studies severe ventricular arrhythmias developed during intrapericardial (i.p.) endothelin-1 (ET-1) infusion. Monophasic action potential duration (MAPD90) increase and significant ST segment elevation preceded the onset of arrhythmias. The aim of this study was to test the antiarrhythmic and anti-ischemic efficacy of the mixed endothelin-A- and -B- (ETA/B) receptor antagonist bosentan (BOS) on ET-1-induced arrhythmias on six mongrel dogs. Ten minutes after an intravenous bolus dose of BOS (10 mg/kg), ET-1 (33 pmol/kg/min) was given into the pericardial space for 30min (BOS group). Six control dogs received only ET-1 infusion (control group). Mean arterial blood pressure (MAP), cardiac output, electrocardiograph (ECG), right and left ventricular endo- and epicardial (RVEND, RVEP, LVEND, LVEP) MAPD90s were recorded. MAP and cardiac output did not change significantly in the BOS group. Significant MAPD90 prolongation was found in all investigated regions of the control group (ET start vs ET 20 min: LVEP, 174 +/- 3 vs 208 +/- 10*; RVEND, 206 +/- 9 vs 241 +/- 12* ms, *p < 0.05), while significant MAPD90 alterations were not observed in the BOS group (basic vs ET 20 min: RVEP, 189 +/- 5 vs 196 +/- 5; LVEP, 199 +/- 5 vs 199 +/- 4; RVEND, 194 +/- 5 vs 195 +/- 6; LVEND, 209 +/- 3 vs 213 +/- 5 ms). Early after depolarizations (EADs) were observed in three control dogs. Severe ventricular arrhythmias [incessant nonsustained ventricular tachycardias (nsVTs) in all cases, sustained VTs (sVTs) in four, ventricular fibrillation (VF) in two instances] were present in the control group, whereas nsVTs were observed only in two dogs in the BOS group. ST segment elevation was more pronounced in the control group than in the BOS group (1.01 +/- 0.2 vs 0.41 +/- 0.07 mV, p < 0.05). In summary, bosentan effectively inhibits intrapericardial ET- 1-induced ventricular arrhythmias, moreover it may have a protective effect against epimyocardial ischemia.

[Atrial fibrillation after open-heart surgery--incidence, prevention and treatment]. / Posztoperatív pitvarfibrillàció okai, gyakorisága, megelözése és kezelése szívsebészeti betegeknél.

Atrial fibrillation is a common problem in the postoperative period following open-heart surgery. The pathogenesis of postoperative atrial fibrillation is likely to be multifactorial, however increased sympathetic activation may play a significant role. The aim of the study was to detect the incidence and possible reasons of atrial fibrillation in the first three postoperative days after open-heart surgery. Atrial fibrillation was detected in a total of 48 patients (mean age 64.8 +/- 8.8 years) of the 302 consecutive patients included in the study. The incidence of atrial fibrillation was 15.9%. In the history of patients with atrial fibrillation paroxysmal or persistent atrial fibrillation occurred in 18 cases. Acute ischaemia, hypopotassemia, high dose catecholamines contributed to the development of arrhythmias in 6, 4 and 4 cases, respectively. Lack of perioperative beta-blocker treatment was seen in 35 cases. Postoperative bleeding and reoperation occurred prior to the onset of atrial fibrillation in 9 instances. The applied antiarrhythmic therapy was metoprolol, amiodarone, propafenon and electrical cardioversion in 33, 21, 4 and 2 cases, respectively. Incidence of atrial fibrillation was found significantly lower in patients receiving beta-blocker premedication (13/181 [7.18%] versus 35/121 [28.9%]). There was no correlation between the incidence of atrial fibrillation and the length of the surgery, aortic-cross clamp time and the number of bypass grafts. Absence of preoperative beta-blocker treatment, previous atrial fibrillation and combined surgery were found to be strong predictors of atrial fibrillation. There was weaker association with increased age. On the basis of the outcome of our study beta-blocker premedication is suggested in most patients undergoing open-heart surgery.