Growth factors in pulmonary arterial hypertension: Focus on preserving right ventricular function.

Pulmonary arterial hypertension (PAH) is a rare and progressive disease, characterized by increased vascular resistance leading to right ventricle (RV) failure. The extent of right ventricular dysfunction crucially influences disease prognosis; however, currently no therapies have specific cardioprotective effects. Besides discussing the pathophysiology of right ventricular adaptation in PAH, this review focuses on the roles of growth factors (GFs) in disease pathomechanism. We also summarize the involvement of GFs in the preservation of cardiomyocyte function, to evaluate their potential as cardioprotective biomarkers and novel therapeutic targets in PAH.

Assessment of the viscosity of the pulmonary artery wall.

Large artery wall viscosity reduces the efficiency of heart/vessel coupling. The aim of the present study was to assess pulmonary artery wall viscosity through comparison of the static (Dst) and dynamic distensibility (Ddyn) of the vessel wall. Right pulmonary artery pressure and diameter was measured in 13 patients and eight healthy volunteers. Ddyn was calculated as the relative change in end-diastolic diameter induced by the pressure pulse, and Dst as the relative change in mean diameter induced by the change in mean pressure during steady-state exercise. Dst did not differ significantly from Ddyn (mean+/-SD 22.8+/-19.2 versus 21.0+/-18.3 10(-3) mmHg(-1)), as tested by paired t-test and analysis of covariance, with age as covariant. End-diastolic diameter increased, whereas Dst and Ddyn decreased as a function of age (r=-0.69 and -0.67, respectively; p<0.01 for both). Ddyn did not change from rest to exercise in spite of a 23+/-16-beats-min(-1) increase in cardiac frequency. Pulmonary artery wall viscosity was negligible and no increase in wall viscosity occurred during cardioacceleration.

Early proarrhythmia during intravenous amiodarone treatment.

We present a case of early (within the first 24 hours) development of malignant torsades de pointes (TdP) associated with intravenous amiodarone therapy. After correction of predisposing factors (heart failure, hypokalemia, digoxin) amiodarone again resulted in torsades. This observation suggests that in patients who have experienced amiodarone-induced proarrhythmia, amiodarone administration under different, more stable clinical conditions may still be hazardous.

Changes in left ventricular contractility with the phase of respiration.

The end-systolic wall stress (sigma(es))-velocity of circumferential fiber shortening (V(cfsc)) relation was defined during the respiratory cycle, in order to obtain a totally noninvasive measure of left ventricular contractility. Eight young, healthy subjects were studied with echocardiography and calibrated carotid pulse tracings, while performing slow paced breathing. Left ventricular sigma(es) vs. V(efsc) relation was determined by fitting linear regression line to data points obtained at different times during the respiratory cycle. Data are given as mean+/-1SD. Left ventricular sigma(es) and V(efsc) exhibited small but significant changes during the respiratory cycle: sigma(es) was highest in late inspiration (56.9+/-4.8 g/cm2) and lowest in late expiration (49.2+/-3.7 g/cm2); inversely, V(cfsc) was lowest during late inspiration (1.18+/-0.17 circ/s) and highest during late expiration (1.34+/-0.20 circ/s). The relation was significant in each subject (r = -0.64+/-0.13) and remained inverse and significant, when it was determined separately for inspiration and expiration (r = -0.61+/-0.17 and -0.68+/-0.12, respectively). At identical end-systolic wall stress, the velocity of shortening was greater during inspiration then expiration, suggesting that contractility was reduced during the expiratory phase. The reduced expiratory contractility might reflect increased vagal influence on the ventricular myocardium.

[Ventricular tachycardia masquerading as supraventricular tachycardia]. / Supraventricularis tachycardiát utánzó kamrai tachycardia.

To distinguish supraventricular tachycardia with aberrancy from ventricular tachycardia is sometimes difficult. It seems to be easy to distinguish the two forms in patients with preexisting bundle branch block: if the QRS morphology during tachycardia is identical to those during at rest the tachycardia is supraventricular, if different, ventricular. We present two cases with preexisting bundle branch block and wide complex tachycardia whose QRS morphologies were almost same to those during normal rest rhythm. The atrioventricular dissociation and the response to adenosine and lidocaine strongly suggests ventricular tachycardia. In these cases ventricular tachycardia masqueraded as supraventricular tachycardia and the identical QRS morphology with the preexisting bundle branch block may suggest a misdiagnosis of supraventricular tachycardia.

Effect of vasoactive drugs on carotid diameter in humans.

We studied whether vasoactive drugs used to determine baroreflex sensitivity influence baroreceptor firing by affecting carotid sinus smooth muscle or simply by stretching the sinus wall through changes in pressure. In six young healthy subjects, the diameter of the carotid artery and its change with arterial pulse were measured with ultrasonography. Blood pressure was measured by Finapres. Phenylephrine and nitroglycerin doses were injected intravenously to raise and lower pressure by approximately 15-25 mmHg. Carotid dimensions increased in all subjects during the phenylephrine-induced rise and decreased during the nitroglycerin-induced fall in pressure. Diastolic diameter changed more than systolic diameter; changes were significantly different from the control value (assessed by single-factor analysis of variance and Scheffé's post hoc test). The systolic pressure-diameter relationship appeared to be nonlinear, with a steeper slope above than below baseline, and contributed significantly to the nonlinearity of the R-R interval-systolic pressure relationship. It is concluded that during drug-induced changes in blood pressure, baroreceptor activity in humans is influenced more by passive stretch than by local smooth muscle contraction.

[Headache as a symptom of angina]. / A fejfájás mint anginatünet.

The authors report two cases where headaches was the only manifestation of severe myocardial ischemia. They had high degree coronaria sclerosis which was demonstrated by angiocardiography in one patient and at autopsy in the second patient. These findings suggest that in the mechanism of headache angina rather the pain perception than generalized vasospasm plays an important role.

[The use of adenosine in the diagnosis and treatment of cardiac arrhythmias]. / Adenozin alkalmazása a szívritmuszavarok diagnosztikájában és kezelésében.

The authors investigated the effect of adenosine or ATP on narrow QRS tachycardia in 56 pts, 3 pts with wide QRS tachycardia 9 pts with suspected latent preexcitation and 10 pts with PVC suspected to be ventricular parasystole. After the bolus iv. administration of adenosine or ATP every SVT was stopped related to AV node (44 pts), but in the rest twelve related to atrial origin of SVT only one automatic atrial tachycardia could be stopped. From the 9 patient suspected to have concealed WPW 2 pts had delta wave during the effect of adenosine, and in four pts parasystole was demonstrated among the pts had varying coupling interval PVC. None of the pts who had wide QRS tachycardia was the tachycardia stopped, but in two cases the supraventricular origin--atrial flutter and tachycardia--was discovered. The authors emphasize the favourable effect of adenosine in narrow complex tachycardia and suggest that it can given safely in wide QRS tachycardia of unknown origin either. The diagnostic effect of adenosine can be used in sinus rhythm too if latent preexcitation or ventricular parasystole is suspected.

Effect of theophylline on periodic breathing in congestive heart failure measured by transcutaneous oxygen monitoring.

The effect of theophylline on periodic breathing was measured by transcutaneous oxygen monitoring in 7 patients suffering from chronic congestive heart failure. Theophylline significantly decreased the frequency of Cheyne-Stokes breathing. Transcutaneous oxygen monitoring proved to be a useful method to follow changes in the breathing pattern. The suggested mechanism of action of theophylline in reducing the incidence of periodic breathing is blockade of adenosine receptors.

[Pathogenic role of a pacemaker in occult infection]. / Pacemaker kóroki szerepe rejtett infectio létrejöttében.

A case of seronegative pacemaker lead infection is presented. The diagnosis based on patient history and echocardiography was proved by removing the infected leads from the beating heart through surgery.

[Rhabdomyoma of unusual manifestation]. / Szokatlan manifesztációjú rhabdomyoma.

According to our knowledge in adult pericardial effusion has never been reported to be present in cases of cardiac rhabdomyoma. We present the history of an adult patient with pericardial effusion due to cardiac rhabdomyoma.

Pericardial effusion as a result of cardiac rhabdomyoma.

A 34-yr-old patient is presented who suffered from chronic pericardial effusion. Surgical exposure revealed a right atrial rhabdomyoma.

[Prinzmetal angina and syncope]. / Prinzmetal angina és syncope.

Authors report an unusual case of variant angina associated with unconsciousness. They were able to prove by coronary angiography the vasospasm of the circumflexus artery which was responsible for the morning attacks of the 35 year old patient with unconsciousness, ST segment elevation and high degree AV block. Unconsciousness was the first and earliest sign of the coronary vasospasm.