Pulmonary Veins in Left Ventricular Failure and Mitral Stenosis

Valvular heart disease

Congenital and acquired valvular disease remains a frequent cause of morbidity and mortality. It presents a diagnostic challenge in all age groups, and often occurs in conjunction with other types of heart disease. Traditional chest radiography provides the earliest opportunity for radiologic diagnosis, hence the need for skill and knowledge in interpreting the radiographic findings. Echocardiography with color flow Doppler measurements is frequently the next modality applied. CT and MR imaging can simultaneously display cardiovascular morphology with greater spatial resolution than ultrasound, and at the same time provide quantitative assessment of cardiac function. The role of diagnostic imaging is therefore crucial, both for primary diagnosis and in the management of valvular heart disease. Furthermore, it is fundamental in evaluating the results of all forms of interventional therapy.

Pulmonary oligemia in aortic valve disease

PURPOSE

To determine whether the severity of the radiographic appearance of oligemia correlates with the severity of cardiac dysfunction.

MATERIALS AND METHODS

Nine readers graded a set of 25 chest radiographs (15 cases of aortic valve disease [AVD], 10 control cases without AVD) for blood volume and ventricular size. Blood volume was graded on a scale of -3 (severe hyperemia) to 0 (normovolemia) to +3 (severe oligemia). Ventricular size was graded on a scale of 0 (normal) to 3 (massively enlarged). The oligemia and ventricular size grades were added to yield the radiographic severity index. Pulmonary capillary wedge pressure, pulmonary arterial pressure, stroke volume, and cardiac output were measured at the time of catheterization.

RESULTS

The five more experienced readers achieved good nonchance agreement (kappa = 0.48; P < .001). They were unanimous in scoring 12 cases as oligemic; variations occurred only in severity assessments. Oligemia was due to emphysema in one case and to AVD in 11. In oligemic cases, radiographic severity correlated significantly with wedge pressure (r = 0.93, P < .001) and pulmonary arterial pressure (r = 0.93, P < .002).

CONCLUSION

Many cases of AVD show oligemia. The severity of oligemia correlates well with hemodynamic abnormality. Oligemia may be caused by atrial-pulmonary-vascular reflex vasoconstriction, low right ventricular output, and possibly high levels of atrial natriuretic factor.

Regional distribution of lung perfusion and ventilation in patients with chronic congestive heart failure and its relationship to cardiopulmonary hemodynamics

To study the relationship between the distribution of pulmonary blood flow, pulmonary ventilation, and pulmonary capillary wedge pressure, we studied six patients with chronic congestive heart failure (CHF) (New York Heart Association classes II and III) at rest and during exercise. We used krypton 81m (81mKr) and technetium 99m (99mTc) to assess lung ventilation and perfusion at rest and during exercise. Hemodynamic measurements were obtained with a balloon floatation thermodilution catheter. At rest, the upper lung zones of patients with CHF received significantly higher proportions of the blood flow compared with previously published data in normal volunteers. During exercise, however, the fractional perfusion to apices did not change, which suggests that apical flow redistribution is already maximized at rest. Measured pulmonary capillary wedge pressure failed to correlate with the upper zone or the ratio of upper-to-lower zone perfusion counts. Our findings suggest that upper zone flow redistribution may be associated with high, normal, or low capillary wedge pressure and therefore does not correlate with the pulmonary capillary wedge pressure in patients with chronic CHF.

Diagnosis of pulmonary hypertension from radiographic estimates of pulmonary arterial size

The reported accuracy of radiographic measurements in predicting pulmonary hypertension is very variable. Measurements of right and left descending pulmonary artery diameter have been reported to provide a correct diagnosis in as many as 98% of patients. A study was carried out to determine the predictive value of measurements made from the chest radiographs of 50 normal subjects and of 27 patients undergoing right heart catheterisation for cardiac or pulmonary vascular disease, taking account of radiographic magnification. After such corrections a right descending pulmonary artery diameter over 16.7 mm or a left descending pulmonary artery diameter of over 16.9 mm distinguished 12 of 23 pulmonary hypertensive subjects, with no false positive results. The diameter was then arbitrarily squared (any differences between patients and control subjects being exaggerated) and the product was divided by either predicted or actual lung volume in an attempt to correct for body size. The new index distinguished 19 of 23 patients with pulmonary hypertension, with one false positive, when the divisor was actual lung volume; when predicted lung volume was used 18 of 23 patients were distinguished, again with one false positive result.

Comparison of computed tomographic lung density with haemodynamic data of the pulmonary circulation

Computed tomographic (CT) lung density measurements were prospectively correlated with pulmonary haemodynamic data in 33 patients with chronic heart disease. Cardiac catheterisation and five specific computed tomographic scans (three at nearly total lung capacity, one at functional residual capacity, and one at residual volume) were performed. There was a significant correlation between anterior lung density and mean pulmonary artery pressure (r = 0.86), pulmonary vascular resistance (r = 0.80), and pulmonary artery wedge pressure (r = 0.65). Lung density, as measured by CT, thus provides a valuable estimate of pulmonary arterial pressure and pulmonary vascular resistance, but is affected by other pathological conditions, such as emphysema and congestional or post-inflammatory fibrosis.

Estimation of pulmonary artery wedge pressure from chest radiograph in patients with chronic congestive cardiomyopathy and ischaemic cardiomyopathy

In order to define the relation between chest x-ray findings and the level of pulmonary artery wedge pressure in patients with chronic congestive cardiomyopathy, 82 patients had chest radiographs before undergoing 92 haemodynamic studies. The studies were divided into three groups according to the level of pulmonary artery wedge pressure (PAWP) (group 1: less than 15 mmHg, group 2: 15 to 24 mmHg, group 3: greater than or equal to 25 mmHg. Venous distribution, interstitial oedema, pleural effusions, left atrial enlargement, and right ventricular enlargement each occurred in less than 10 per cent of group 1 studies. Radiological abnormalities generally distinguished group 1 from group 2, but none except cardiothoracic ratio distinguished group 2 from group 3. Cardiothoracic ratio correlated best with pulmonary artery wedge pressure (r = 0.70). Alveolar oedema was uncommon when PAWP greater than or equal to 25 mmHg, occurring in 32 per cent of group 3 studies. Stepwise multiple linear regression analysis showed that cardiothoracic ratio, alveolar oedema, interstitial oedema, and left atrial size each contributed independently to the prediction of PAWP. The regression analysis improved the accuracy of the estimation of PAWP from the findings noted on standard chest radiographs.

Prediction of left heart filling pressure and its sequential change in acute myocardial infarction from the terminal force of the P wave

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