Selection of Techniques for the Measurement of Left Heart Pressures

Abstract

The technique of venous catheterization gives only indirect information about lesions of the left side of the heart. Analysis of mitral valve disease was made possible by the discovery that a venous pressure pulse could be obtained from a catheter wedged in a peripheral pulmonary artery (Lagerlof and Werko, 1949;Hellems et al., 1949). The form of the arterial pulse has been used for the indirect evaluation of aortic valve disease (Hancock and Abelman, 1957;, and in recent years several techniques for direct measurement of left heart pressures have been introduced. Puncture of a cardiac chamber is usually necessary, and the risk of these methods is considerably greater than that of the right heart catheterization.Whenever haemodynamic study is thought necessary, the type of investigation to be performed must be decided with regard to the abnormality present and the information required. The value of the data to be obtained must be considered in relation to the morbidity of the procedure. Right heart catheterization alone is often decisive, and left heart pressure measurements should be reserved for situations in which they will provide critical information.In the present study, emphasis is placed on the accurate measurement of the pressure gradient across the mitral or aortic valve, with simultaneous estimation of the cardiac output. Assessment of regurgitant flow by indicator dilution (Carleton et al., 1960; Warner and Toronto, 1958) METHODSThe methods used have been described previously (Davila et al., 1959). Central arterial pressure was recorded continuously using the Seldinger (1953) method. Right heart catheterization was performed for the measurement of pulmonary arterial and wedge pressures. Left atrial pressures were obtained by transbronchial puncture using a slotted bronchoscope which could be removed leaving the needle in place. Left ventricular pressures were recorded by direct puncture through the anterior chest wall (Brock et al., 1956) or by retrograde arterial catheterization using a Cournand catheter inserted in the right brachial artery (Voci and Hamer, 1960).Simultaneous pressure measurements were made on either side of the mitral or aortic valves while cardiac output was estimated by the Fick method. Pressures were recorded with P23Db Statham strain-gauges and a 4-channel direct writing Sanborn Polyviso with optimal damping, and were replotted on the same scale without correction for phase lag. The base-line for all pressure measurements was the middle of the chest at the level of the second costal cartilage . The Ry/v ratio (Owen and Wood, 1955) was calculated from left atrial pressures adjusted to a base-line at the level of the sternal angle. Blood oxygen contents were determined by the Van

Retrograde Arterial Catheterization of the Left Heart

“…22 Of the two deaths, one occurred 5 days following catheterization in an 11-month-old baby with complex anomalies including a single ventricle, transposition of Ciculation, Volume XXIX, May 1964 the great vessels, and severe coarctation of the aorta. On postmortem examination death appeared to be due to renal artery thrombosis, which may have been related to the arterial catheterization.…”

Extended Suprasternal Puncture

“…However, he had been using a much larger needle than that recommended by Radner and there seems little doubt that the thinness of the needle is the main reason for the safety of suprasternal puncture. Hamer and Dow (1961) suggest that the use of such a long thin needle makes it difficult to obtain undamped records but this has not been our experience.…”

“…The systolic blood pressure, on the other hand, was fairly consistently, but not usually markedly, raised during suprasternal puncture; similar and rather more marked changes occurred during left ventricular puncture. As Hamer and Dow (1961) pointed out, changes in cardiac output and heart rate do not affect the calculated valve area, provided that all the relevant information is obtained simultaneously; changes in blood pressure, however, are likely to alter the degree of mitral regurgitation (Braunwald, Welch, and Morrow, 1958) and, in this respect, suprasternal puncture is less than ideal. Although no data are available, it is probable that the same criticism applies to the transthoracic and bronchoscopic approaches; the effect of transseptal catheterization is less predictable.…”

Retrograde Catheterization of the Systemic Circulation with the Loop-End Catheter

“…Aortic valve disease prevented entry into the left ventricle in 19 and there was an unexplained failure in one patient with an apparently normal valve. Aortic valve disease prevented entry into the left ventricle in 19 and there was an unexplained failure in one patient with an apparently normal valve.…”