[2-dimensional echocardiography in the evaluation of right ventricular volume and function. Comparison with echocardiography]. / Dvourozmerná echokardiografie pri hodnocení objemu a funkce pravé komory. Srovnání s echokardiografií.

Using two-dimensional echocardiography (ECHO), the authors examined within one week preceding right-sided catheterization of the right ventricle (RV) 44 patients. Of three tested ECHO techniques for calculation of right ventricular volumes and/or function the best correlations were obtained by the method of evaluation of area-length of the right ventricle from two orthogonal projections (apical 4-cavity and subcostal with visualization of the outflow portion of the RV). The following correlations were assessed: telediastolic volume--r = 0.831, telesystolic volume--r = 0.815 stroke volume--r = 0.810 and ejection fraction (EF)--r = 0.752 (p less than 0.001 for all correlations). The tested method enables us at the same time to screen at least existing right ventricular dysfunction (sensitivity 0.68; specificity 0.82). In the presence of tricuspidal insufficiency (TI) increase in right ventricular function occurs which may mask its existing failure (dependence of EF on the mean pressure level in pulmonary artery was proved only in patients without TI--r = 0.594). We assume that information on right ventricular function is important not only in diseases affecting primarily the right heart but also in advanced stages of left-sided failure. Follow-up of the natural course of the disease and the effect of provided treatment by the non-invasive ECHO method is thus useful not only in research but also in clinical practice.

Three echocardiographic methods in right ventricular function evaluation.

We employed two-dimensional echocardiography for the assessment of right ventricular (RV) volumes and/or function in a series of 44 patients. The results of three different echocardiographic approaches were compared with the data obtained from single-plane RV angiography following ultrasound within a 7-day interval. Only the echocardiographic area length method with two orthogonal imaging planes employed (apical 4-chamber and subcostal projections) yielded the beneficial results. The correlations between echocardiographic and angiographic RV volume estimates were rather high (end-diastolic volume: r = 0.83, end-systolic volume: r = 0.82, stroke volume: r = 0.81) and satisfactory in ejection fraction (r = 0.75). Using the method mentioned, the differentiation of patients with an angiographic evidence of RV failure (echocardiographic ejection fraction less than 0.55) from those without it was possible with a sensitivity of 0.68 and a specificity of 0.82. Concerning the clinical impact of the presented study, we can recommend the technique in question as a screening procedure for the detection of changes in RV function exceeding 12% (95% confidence limits).

The effect of acute and chronic nitrate administration in precapillary and postcapillary pulmonary hypertension.

The effect of nitrates was monitored in 16 patients with precapillary, and in 12 patients with postcapillary pulmonary hypertension (PH). The patients had haemodynamic examination on acute administration of 10 mg of isosorbide nitrate (ID) in infusion and after 2-month therapy with 120 mg of isosorbide dinitrate retard daily. Acute ID administration decreased filling pressure of both ventricles, pulmonary and aortic pressure, pulmonary and systemic resistance and increased blood flow. No significant difference was found between the two types of PH. Long-term administration resulted in a statistically significant decrease in filling pressure (in both ventricles) and pulmonary pressure, even though the decrease was less pronounced than those seen following acute administration. Again, no statistical differences were noted between the two types of PH. While acute administration of nitrates decreases both preload and afterload, chronic administration decreases only preload. The implications of this finding for therapeutic practice are discussed.

Long-term effect of isosorbide dinitrate and nifedipine, singly and in association, in patients with chronic heart failure.

The effect of 2-month treatment with isosorbide dinitrate (120 mg day-1), nifedipine (2 x 20 mg day-1) and their combination has been assessed in 16 patients with mild to moderate chronic cardiac failure. Isosorbide dinitrate decreased right atrial (-23%), pulmonary wedge (-20%) and pulmonary arterial (-17%) pressures but did not significantly change either cardiac output or systemic and pulmonary vascular resistance. Nifedipine increased cardiac output (+13%) and decreased systemic and pulmonary vascular resistance (both -17%) with no change of pressures. Combined therapy with both drugs decreased ventricular filling pressures (-8% and -15%), systemic (-20%) and pulmonary (-13%) arterial pressures, increased cardiac output (+26%) and decreased both systemic (-29%) and pulmonary (-29%) vascular resistances. Changes during exercise were almost the same as at rest. The effect of both drugs was more pronounced in patients with more severely pathological haemodynamic measurements before treatment. We conclude that combined treatment with both preload- and afterload-reducing agents can preserve or even potentiate a favourable haemodynamic effect of individual drugs.

[Non-invasive diagnosis of pulmonary hypertension: Doppler versus echocardiography]. / Neinvazívní diagnostika plicní hypertenze: Doppler versus echokardiografie.

The authors examined a group of 50 patients incl. 28 (56%) with pulmonary hypertension (PH) at rest, mostly postcapillary. Using a Doppler device, they measured the acceleration time (ACT) in the outflow tract of the right ventricle and trunk of the pulmonary artery. Under conditions of concurrent Doppler and direct, catheterization measurements the authors found a close correlation between ACT and the mean pressure in the pulmonary artery (r = -0.88), which was, however, not confirmed after a 1-10 day interval (r = = -0.64). The authors conclude that Doppler ACT reflects only the actual pressure in the pulmonary circulation. The authors found a close correlation between ACT values in the right ventricular outflow tract and the pulmonary artery (r = 0.95), and no significant difference. Comparison of Doppler diagnosis of PH with former echocardiographic methods revealed unequivocally the priority of the Doppler method. Failure of echocardiography is most probably associated with the postcapillary type of PH in the group of patients and does not rule out the validity of original findings in precapillary PH. Rapid and easy assessment along with a simpler interpretation is in favour of the Doppler technique.

Long-term reduction of pulmonary hypertension in interstitial lung fibrosis by isosorbide dinitrate.

The effect of isosorbide dinitrate (ID) on the development of pulmonary hypertension (PH) has been examined in 18 patients with idiopathic diffuse interstitial lung fibrosis (IDILF) during two years of treatment. All patients responded favourably to acutely administered ID by a decrease in pulmonary vascular resistance (PVR) by 38 +/- 13% and of the pulmonary arterial pressure (PAP) by 35 +/- 11%. Two years ID therapy led to sustained haemodynamic improvement in patients in whom blood gases were stable PAP was reduced from 38 +/- 5 to 30 +/- 6 mmHg and PVR from 483 +/- 197 to 364 +/- 175 dyne s cm-5. No haemodynamic changes were noted in the subjects with progressive hypoxaemia whereas steady deterioration of central haemodynamics was recorded in those patients who died during the follow-up. It is concluded that some patients with IDILF and PH may benefit from long-term ID treatment, but that the outcome of this treatment cannot be reliably predicted from the results of the initial first ID administration.

Assessment of stroke volume and cardiac output by Doppler echocardiography.

The authors used the pulse and continuous-wave Doppler technique to perform 51 measurements of stroke volume and cardiac output in 37 persons. Results were compared with those obtained using Fick's principle of thermodilution (immediately subsequent or simultaneous). Regression analysis showed a close correlation between Doppler and haemodynamic values - r = 0.86 for stroke volume and 0.94 for cardiac output (p less than 0.001). Using the paired t-test, the methods did not differ significantly. Standard deviation of Doppler stroke volume values from reference haemodynamic values was 10%, and only two measurements differed by more than 25%. Doppler determination of cardiac output can be therefore recommended as an alternative method in patients with high-quality echo Doppler recordings.

A critical appraisal of M-mode echocardiography in mitral stenosis.

The reliability of M-mode echocardiography in confirming mitral stenosis and in assessing its severity was tested in 39 patients with mitral stenosis. None of the conventional echocardiographic signs of mitral stenosis is absolutely reliable. Unless at least 2 signs are combined, the diagnosis is not conclusive (sensitivity = 0.97, specificity = 1.00). Of a number of echocardiographic parameters and equations recommended (as tools) to determine the severity of mitral stenosis, the early diastolic velocity of anterior leaflet opening (EF) is the only one with a statistically significant relationship to the mitral valve area (MVA) calculated by Gorlin (r = 0.712, p less than 0.001), and this only in uncomplicated unoperated mitral stenoses, but not in mitral restenoses and combined mitral defects. Even the recently published Seitz's equation for calculating MVA from echocardiographic data is not reliable. M-mode echocardiography is an excellent technique for the primary diagnosis of mitral stenosis. However, it is not suitable to even an approximate assessment of its haemodynamic severity.

Comparison of M-mode echocardiography and angiography in the evaluation of left ventricular hypertrophy.

The authors analysed in a group of 82 patients with a symmetric left ventricle and a homogeneous ventricular wall thickness the reliability of M-mode echocardiography in recognizing left ventricular hypertrophy. In concentric hypertrophies, a sufficient diagnostic criterion is ventricular wall thickness. Measurement of the interventricular septum offers a better correlation with angiographic values (r = 0.609, p less than 0.001) than measurement of the posterior wall (r = 0.358, p less than 0.01); a correct diagnosis can be determined in 84%. In excentric hypertrophies, the hypertrophy must be assessed on the basis of calculating the left ventricular mass. The most accurate of echocardiographic methods proved to be the calculation according to the authors' own formula (r = 0.760, p less than 0.001), which recognizes left ventricular hypertrophy correctly in 85%. The diagnostic correctness of Teichholz' formula is 80% and of the cubic formula 74%. Fortuin's equations proved to be of no value for documenting ventricular hypertrophy. In a group of 13 patients with hypertrophic cardiomyopathy, the correlation between angiographic and echocardiographic values of the left ventricular mass was very low (r = 0.534, p = 0.05).

Septal aneurysm with associated anomalies.

A 15-year-old boy had a history of a functional systolic murmur with systolic and diastolic murmurs and radiological evidence of left ventricular hypertrophy. The angiocardiogram demonstrated an aneurysm of the membranous septum, bicuspid aortic valve, dilatation of the left subclavian artery and left common carotid artery. Echocardiography showed a holosystolic prolapse of the mitral valve with mitral insufficiency and a bicuspid aortic valve with insignificant incompetence of the aortic valve. Classical TM mode echocardiography did not show an aneurysm of the membranous septum.

Left ventricle in mitral stenosis.

The authors investigated the left ventricular systolic function and diastolic characteristic in 25 patients with mitral stenosis and compared the results with findings in 25 healthy subjects. The patients with mitral stenosis differed from the control group by elevated left ventricular filling pressure, greater left ventricular end-diastolic volume, reduced ejection fraction, and decreased calculated left ventricular compliance. Pathological values of these indicators, however, were infrequent and as a rule only slightly exceeded the normal limits. The decrease in left ventricular compliance had significant correlations with the degree of pulmonary arterial hypertension, elevation of right ventricular filling pressure, the ratio of filling pressures of both ventricles, and left ventricular end-systolic eccentricity. Consequently, the authors infer that the main factor decreasing the left ventricular compliance in mitral stenosis is the aberrant geometry of the ventricle. The authors also point out the correlations between the left ventricular systolic function and diastolic characteristics in mitral stenosis, and assume that this affection represents a complex, although not too advanced, disturbance of left ventricular function.