Exercise echocardiography in dilatative cardiomyopathy

Using M-mode echocardiography under 2-D control at rest and during ergometer exercise (ex), we examined 15 patients (pat) with angiographically moderate diffuse left ventricular (LV) contraction impairment (mean enddiastolic volume index 115 ml/m2, mean ejection fraction 58%) (group DCM I). The aim of the study was to look for differences in LV behavior under exercise within this patient group, with a view to aiding diagnosis. These pat were compared to 10 normal subjects (N) and 10 pat with advanced dilatative (congestive) cardiomyopathy (enddiastolic volume index 135 ml/m2, ejection fraction 44%) (DCM II). Even at rest, the LV diameters and the fractional shortening (FS) in the group DCM I differed significantly from those in N, and in the case of the mean FS the difference increased on ex (rest p less than 0.05, exertion p less than 0.0005). In none of the three groups did the enddiastolic diameter undergo any significant change on ex. The endsystolic diameter decreased in N by an average of 5.2 mm (p less than 0.0005); at 2.8 mm (p less than 0.005), the decrease (DCM I vs N p less than 0.005) was distinctly slighter to be observed in DCM I; in DCM II it was no longer significant. Within the group DCM I, 4 pat showed a behavior on ex that was not what the values at rest would have suggested. 2 pat showed a physiological reaction on ex despite a restricted function at rest; however, in 2 patients with relatively good values at rest, the FS decreased on ex. According to these findings, a restriction of LV function is to be recognized echocardiographically more clearly on ex than at rest, especially in low-level dilatative cardiomyopathy (DCM). In individual cases, a varying increase in LV functional impairment is to be observed during ex, or even generalized physiological reaction, which would not be expected from the echocardiogram at rest. Thus the results of the examination present a differentiated basis for the observation of the course of the disease, especially in pat with a moderate DCM.     

Course of dilatative hypertrophic cardiomyopathy

Five patients with hypertrophic cardiomyopathy developed left-ventricular dilatation and congestive heart failure during an observation period of 16-29 years. In one patient cardiac transplantation had to be performed. The initial predominant symptoms of outflow-tract obstruction and diastolic dysfunction developed into progressive left-ventricular systolic failure. The question of whether this is a well-defined subgroup of patients with hypertrophic cardiomyopathy, or whether hypertrophic cardiomyopathy turns into a phase of left-ventricular dilatation and failure after some years remains to be elucidated by long-term studies.     

Familial hypertrophic cardiomyopathy associated with Wolff-Parkinson-White syndrome

Familial hypertrophic cardiomyopathy (HCM) with Wolff-Parkinson-White (WPW) syndrome is extremely rare and associated with a high risk of ventricular tachyarrhythmia and sudden death. We report a familial form of hypertrophic cardiomyopathy associated with Wolff-Parkinson-White syndrome in two siblings 7 and 12-year-old. These patients showed progression to left ventricular dilatation. Early recognition and treatment of such forms can improve such evolution and the risk of sudden death.     

Giant right atrial diverticulum: an unusual cause of Wolff-Parkinson-White syndrome

A case of a giant right atrial diverticulum associated with neonatal supraventricular tachycardia is reported. The electrocardiogram in sinus rhythm showed pre-excitation that may have been caused by the right atrial diverticulum adhering to the right ventricle.     

Thrombocyte activity in dilatative cardiomyopathy and latent cardiomyopathy compared to coronary heart disease

In a comparative study on the pathomechanism of myocardial hypoxia we determined a parameter each of platelet activity and thrombin activity in 46 patients with angina pectoris, i.e., 15 patients with dilatative cardiomyopathy (DCM), 15 patients with latent cardiomyopathy (LCM) and 16 patients with coronary heart disease (CHD) compared to 15 normal subjects (N). beta-thromboglobulin (beta TG) and fibrinopeptide A (FPA) were measured both at rest (I) and after symptom-limited maximal exercise (II) in plasma. In N, beta TG was not increased in any case, neither at rest nor on exertion (I: 20.5 +/- 6.1 ng/ml, II: 22.4 +/- 6.7 ng/ml). Patients with LCM did not differ significantly from N (I: 20.9 +/- 6.1 ng/ml, II: 22.7 +/- 7.9 ng/ml). beta TG values of some patients with DCM and CHD were increased at rest and especially under exercise (DCM I: 27.9 +/- 9.6 ng/ml, vs. N p less than 0.025; II: 49.9 +/- 45.5 ng/ml, vs. N p less than 0.01; CHD I: 25.2 +/- 7.7 ng/ml, vs. N p less than 0.05; II: 38.6 +/- 34.3 ng/ml, vs. N p less than 0.01). Patients with DCM developing significant angina under exercise showed a higher beta TG under these exercise conditions than those with mild or no angina (p less than 0.01). In patients with coronary heart disease, this correlation was not to be found. With regard to FPA the four investigated groups differed in an analogous way, as they did with regard to beta TG; but only a weak correlation within both values was shown.(ABSTRACT TRUNCATED AT 250 WORDS)     

Septic cardiomyopathy as a cause of long QT syndrome

A 63-year-old woman admitted with 2:1 infranodal atrioventricular block subsequently developed ventricular dysfunction incident to septic syndrome. Concomitant changes included an abnormally prolonged QTc interval (600 ms) and the occurrence of torsade de pointes. Restoration of a normal QTc interval and cessation of torsade de pointes was coincident with return of normal ventricular function and remission of sepsis. This report supports the view that sepsis-induced cardiomyopathy is another cause of the long QT syndrome.     

Giant right atrial diverticulum: an unusual cause of Wolff-Parkinson-White syndrome.

A case of a giant right atrial diverticulum associated with neonatal supraventricular tachycardia is reported. The electrocardiogram in sinus rhythm showed pre-excitation that may have been caused by the right atrial diverticulum adhering to the right ventricle.     

Conduction over an isthmus of atrial myocardium in vivo: a possible model of Wolff-Parkinson-White syndrome

Antiarrhythmic drugs appear preferentially to prolong refractoriness of accessory pathways compared with atrial or ventricular muscle in patients with the Wolff-Parkinson-White syndrome. This response may be due to intrinsic properties of accessory pathways or to depressed conduction associated with a narrow strip, or isthmus, of tissue. To test the latter possibility, in 16 anesthetized dogs we surgically isolated a portion of the right atrial myocardium in the form of an ellipse (10 to 25 X 8 to 15 mm). The ellipse was connected to the body of the right atrium by a narrow isthmus (cross-sectional area [CSA] 1 to 13.5 mm2) and was perfused by the sinus node artery or its branch. Diastolic threshold (mean +/- SE 0.16 +/- 0.05 vs 0.13 +/- 0.02 mA) and effective refractory period (ERP; 144 +/- 4 vs 139 +/- 5 msec) were the same proximal and distal to the isthmus. In eight dogs, determination of the ERP of the isthmus was limited by the ERP of the atrial tissue proximal and distal to the isthmus, and the CSA of the isthmus in these dogs was significantly larger than that in the remaining seven dogs in which the ERP of the isthmus could be determined (7.4 +/- 1.4 vs 3.2 +/- 0.6 mm2, p less than .05). The shortest pacing cycle length (PCL) with 1:1 conduction from the proximal to the distal segments did not differ from that in the opposite direction in 16 dogs (154 +/- 9 vs 153 +/- 7 msec). The CSA of the isthmus correlated inversely with the shortest PCL with 1:1 conduction in both directions via the isthmus (r = -.84, p less than .01). Vagal stimulation shortened the shortest PCL with 1:1 conduction from the distal to the proximal segment (153 +/- 14 vs 143 +/- 12 msec, p less than .02), but not in the opposite direction. Procainamide (10 to 20 mg/kg iv, serum concentration 8.6 +/- 0.8 micrograms/ml) prolonged the ERP of the proximal site from 145 +/- 5 to 170 +/- 5 msec (p less than .001), the ERP of the distal site from 143 +/- 6 to 168 +/- 6 msec (p less than .001) in 12 dogs, and the shortest PCL with 1:1 conduction (proximal to distal from 149 +/- 8 to 204 +/- 17 msec, p less than .001; distal to proximal from 149 +/- 7 to 197 +/- 12 msec, p less than .001) in 14 dogs.(ABSTRACT TRUNCATED AT 400 WORDS)     

Dilated cardiomyopathy: an unexpected complication of rapidly conducted atrial flutter in the Wolff-Parkinson-White syndrome

This report describes a 34-year-old male with the Wolff-Parkinson-White syndrome who presented with the unusual finding of a tachyarrhythmia-induced cardiomyopathy secondary to atrial flutter with 1:1 conduction through a left-lateral accessory pathway. Catheter ablation of the accessory connection resulted in complete normalization of cardiac function.     

Adenosine monophosphate-activated protein kinase disease mimicks hypertrophic cardiomyopathy and Wolff-Parkinson-White syndrome: natural history

OBJECTIVES: The aim of this study was to investigate the clinical expression of adenosine monophosphate-activated protein kinase (AMPK) gene mutations (PRKAG2) in adenosine monophosphate (AMP) kinase disease based on 12 years follow-up of known mutation carriers and to define the prevalence of PRKAG2 mutations in hypertrophic cardiomyopathy (HCM). BACKGROUND: Adenosine monophosphate-activated protein kinase gene mutations cause HCM with Wolff-Parkinson-White syndrome and conduction disease. METHODS: Clinical evaluation of 44 patients with known AMP kinase disease was analyzed. Mutation analysis of PRKAG2 was performed by fluorescent single-strand confirmation polymorphism analysis and direct sequencing of abnormal conformers in 200 patients with HCM. RESULTS: Only one additional mutation was identified. The mean age at clinical diagnosis in the 45 gene carriers was 24 years (median 20 years, range 9 to 55 years). Symptoms of palpitation, dypspnea, chest pain, or syncope were present in 31 (69%) gene carriers; 7 (15%) complained of myalgia and had clinical evidence of proximal myopathy. Skeletal muscle biopsy showed excess mitochondria and ragged red fibers with minimal glycogen accumulation. Disease penetrance defined by typical electrocardiogram abnormalities was 100% by age 18 years. Thirty-two of 41 adults (78%) had left ventricular hypertrophy (LVH) on echocardiography, and progressive LVH was documented during follow-up. Survival was 91% at a mean follow-up of 12.2 years. Progressive conduction disease required pacemaker implantation in 17 of 45 (38%) at a mean age of 38 years. CONCLUSIONS: The AMP kinase disease is uncommon in HCM and is characterized by progressive conduction disease and cardiac hypertrophy and includes extracardiac manifestations such as a skeletal myopathy, consistent with a systemic metabolic storage disease. Defects in adenosine triphosphate utilization or in specific cellular substrates, rather than mere passive deposition of amylopectin, may account for these clinical features.