Characterization of left ventricular external wall motion in man by video dimension analyzer (Vidian)

Several investigators have described close relationships between left ventricular wall motion and physiologic cardiac events. Using an improved wall motion tracking devide (Vidian) in studies of 30 patients, we have compared the dynamics of left ventricular wall motion, recorded noninvasively, with high fidelity left ventricular and aortic pressures, intracardiac phonocardiograms, apexcardiograms, and cyclic left ventricular volume curves obtained during cardiac catheterization. Wall motion tracking signals comprised: pre-ejection outward deflection commencing with the first component of the first heart sound and coincident with the pre-ejection phase of the left ventricular pressure and apexcardiogram; a sharp descent during ejection, commencing with the "E" point of the apexcardiogram and with the onset of the upstroke of the aortic pressure; end ejection nadir, synchronous with the dicrotic notch of the aortic pressure; a nadir representing cessation of inward displacement, presumably reflecting slight inertial motion of the wall; a brief period of isovolumic relaxation which terminated synchronously with the "O" point of the apexcardiogram; rapid, then slow filling waves, coincident with those of the apexcardiogram, and demarcated by a transitional angulation synchronous with the third heart sound; and "a" wave, occurring simultaneously with that of the apexcardiogram. Ventricular wall motion tracking signals also corresponded to curves representing cyclic changes in left ventricular minor radius, and chamber volume derived from cineventriculograms. In 10 patients with abnormal contraction patterns detected by biplane cineventriculography, anomalous deflections were also recorded during ejection by the Vidian. Left ventricular wall motion tracking with the Vidian: 1) provides a sensitive index for timing of intracardiac events, 2) reflects cyclic changes in ventricular volumes and minor dimensions, 3) provides a convenient noninvasive technique for detection of regional asynergy involving the lateral left ventricular wall, and 4) by correlation with simultaneous ventricular pressure measurements, may provide useful information regarding left ventricular pressure/segment dimension relations.

Abnormal left ventricular catheter motion: an ancillary angiographic sign of left atrial myxoma

The normal motion of a left ventricular catheter parallels that of the aortic root; it moves anterior during systole and posterior during diastole. In contrast, a prolapsing left atrial myxoma causes paradoxical motion of the catheter; posterior during systole and anterior during diastole. Paradoxical motion was found in each of five cases of prolapsing left atrial myxoma (no false negatives), and in six out of 61 controls (six false positives). In the false positive cases, the catheter was not positioned on the ventricular floor and usually only minor degrees of abnormal motion were present. Paradoxical motion of the left ventricular catheter is an ancillary angiographic finding in prolapsing left atrial tumor.

Transmission of audible praecordial gallop sounds to right supraclavicular fossa

To evaluate the significance of audible gallop sounds in the right supraclavicular fossa we performed simultaneous external heart sound recordings at 50 and 100 Hz at the left ventricular apex, left sternal border, and right supraclavicular fossa in 50 patients with audible gallop sounds at the left ventricular apex. In each patient heart sounds were recorded with a simultaneous jugular phlebogram, apex cardiogram, and carotid pulse tracing. In 44 patients an apical fourth heart sound coincident with the 'a' wave of the apex cardiogram was recorded, and in 32 (73%) the fourth heart sound was audible and recordable in the right supraclavicular fossa. A left ventricular third heart sound, coincident with the rapid filling wave of the apex tracing, was present in 25 patients but was recorded in the right supraclavicular fossa in only 7 (28%). Intracardiac phonocardiography (high-fidelity catheter) was performed in six patients with left ventricular gallop sounds and in each instance arterial transmission of the third or fourth heart sound, or both, was present. Five additional patients had a prominent jugular venous 'a' wave, but only two had a soft parasternal fourth heart sound. Intracardiac phonocardiography in these five patients failed to reveal transmission of right ventricular gallop sounds to the superior vena cava. We conclude that since left ventricular gallop sounds commonly are transmitted to the right supraclavicular fossa auscultation in this area is often helphful in their detection. In addition, a prominent jugular venous 'a' wave sometimes produces recordable presystolic vibrations that are occasionally audible as well.

Functional evaluation of the porcine heterograft in the mitral position

In vivo function of glutaraldehyde-fixed porcine heterografts used for mitral valve replacement was evaluated by cardiac catheterization in 14 of our first 33 patients who have undergone mitral valve replacement with this prosthesis. Diastolic gradients were present in each patient. Average mean diastolic gradient was 6.5 mm Hg for the group, and average end-diastolic gradient was 3.0 mm Hg. Calculated mitral valve orifice areas ranged from 0.92 cm2 to 3.39 cm2, the average being 2.15 cm2. With rapid pacing (heart rate approximately 140), average mean gradient increased by 6 mm Hg. No patient had mitral regurgitation. Two patients had calculated mitral valve areas of 1 cm2 or less; one of these was found at postmortem examination to have thrombus adherent to the ventricular aspect of 2 of the 3 valve leaflets, rendering them immobile.

Determination of site of infection in endocarditis

Medical-surgical treatment of antibiotic refractory endocarditis requires determination of the site of infection, which is not always possible with conventional cardiac catheterization. The cases of two patients with right-sided endocarditis who survived after combined medical-surgical therapy are presented. One had persistent Pseudomonas aeruginosa bacteremia and three possible sites of infection. Multiple quantitative blood cultures proximal and distal to each suspected site indicated the pulmonary valve alone was infected. The second had sustained bacteremia with three enteric organisms and no apparent valvular abnormality. Quantitative cultures excluded the abdomen as the continuing source of bacteremia and suggested the tricuspid valve was infected. This was confirmed by a second catheterization using multiple cultures in conjuction with dye dilution studies, intracardiac phonocardiography, and angiography. These bacteriologic and cardiologic techniques may be especially useful in detecting right-sided endocarditis and may also be helpful in detecting concomitant infection of both sides of the heart.

Comparison of isovolumic and ejection phase indices of myocardial performance in man

Indices derived from both the isovolumic and ejection phases of left ventricular systole have been advocated as a means of defining the basal level of contractility, but their comparative reliability for separating patients with obvious myocardial disease from a normal population has not been documented. Accordingly, indices of myocardial function were measured and compared in 36 patients, 22 with normal and 14 with abnormal ventricular function, using optimal techniques of pressure measurements by cathetertip micromanometry, signal digitizing at 1 msec intervals with averaging of multiple beats, and left ventriculography by biplane cineangiography. Isovolumic indices derived from developed pressure (DP), including V max, dP/dt/DP at DP = 5, 10, and 40 mm Hg, demonstrated no sensitivity for identifying depressed myocardial function ( P > 0.1 in each instance). Using total pressure (TP), V max, peak (dP/dt/TP), and peak dP/dt served to separate the two patient populations from a statistical standpoint ( P < 0.001), but individual values in the two groups showed considerable overlap. By contrast, the simplified ejection phase velocity indices, mean velocity of circumferential fiber shortening (mean Vcf) and mean normalized systolic ejection rate (MNSER) showed superior sensitivity for identifying normal and abnormal patient groups and manifested minimal overlap of individual values ( P < 0.001). These observations indicate that, in patients with diffuse myocardial involvement, isovolumic indices are not reliable for detecting depressed myocardial function and that ejection phase contractile indices appear to offer a preferable mode for assessing myocardial function in the basal state.

Postoperative hemodynamic evaluation of a new fabric-covered ball-valve prosthesis

Previous in vitro and in vivo experimental studies have indicated that insertion of the Braun-wald-Cutter fabric-covered ball-valve prosthesis results in negligible thromboembolic complications and hemodynamic performance comparable to that of noncovered mitral and aortic ball-valve prostheses. To assess the clinical efficacy of this fabric-covered valve prosthesis, 35 patients have been followed for 4 to 26 months (540 patient-months) after mitral and/or aortic valve replacement, and 13 have had extensive hemodynamic re-evaluation.

In eight patients with the mitral valve prosthesis, the mean diastolic gradient averaged 4.8 mm Hg (range 0 to 8) and the end-diastolic gradient 0.8 mm Hg (range 0 to 2) at a time when the mean heart rate was 75 beats/min (range 50 to 100) and the cardiac output averaged 5.1 L/min (range 3.4 to 8.0). The calculated effective mitral valve orifice size averaged 2.68 cm 2 (range 1.92 to 3.46). In six patients with the aortic valve prosthesis, the average peak systolic gradient was 13 mm Hg (range 0 to 22), and the mean systolic gradient averaged 14.5 mm Hg (range 0 to 24) when the mean heart rate was 82 beats/min (range 64 to 120) and the cardiac output averaged 6.2 L/min (range 3.2 to 9.3). The average effective aortic valve size in the five patients with a mean systolic transvalvular gradient was 1.41 cm 2 (range 1.26 to 1.62).

Only one postoperative thromboembolic complication has been observed, and this occurred in a patient with atrial fibrillation and a large left atrium three weeks after discontinuing anticoagulant therapy because of gingival bleeding.

These data indicate that use of the fabric-covered Braunwald-Cutter ball prosthesis produces few thromboembolic complications and a satisfactory hemodynamic result.

Assessment of left ventricular performance in man. Instantaneous tension-velocity-length relations obtained with the aid of an electromagnetic velocity catheter in the ascending aorta

A three-dimensional construct of the tension-velocity-length relations of the intact human heart has been obtained in 17 patients by measurement of instantaneous ascending aortic flow velocity, left ventricular (LV) high-fidelity pressure, and end-diastolic volume. Left ventricular instantaneous volume was determined by subtracting the integral of the flow trace, obtained with an electromagnetic velocity catheter, at each 5-sec interval from the end-diastolic volume measured on a biplane left ventriculogram. By utilizing a thin-walled spherical model for the LV, instantaneous velocity of circumferential fiber shortening (V CF ), wall tension, and circumferential length were calculated and plotted with the aid of a computer on a three-dimensional perspective graph. The resulting tension-velocity-length relations in seven patients with normal LV function were clearly separated from those of 10 patients with abnormal LV function. Of velocity indices alone, peak V CF in circumferences/sec (circ/sec) provided the best statistical separation between the groups with normal and abnormal ventricular function (2.54 ± 0.18 [ sem ] circ/sec and 1.09 ± 0.15 circ/sec, respectively) ( P < 0.001). The time to peak V CF averaged 194 ± 13.2 msec and 167 ± 9.3 msec in the patients with normal and abnormal ventricular function, respectively ( P > 0.05). Likewise, V CF at peak tension was significantly greater in the patients with normal as opposed to abnormal LV function (1.77 ± 0.10 and 0.93 ± 0.15 circ/sec, respectively) ( P < 0.001). Time to peak tension was 138 ± 14.8 msec and 182 ± 17.1 msec in the normal and abnormal patients, respectively ( P > 0.05). Mean V CF also served to separate the two groups, averaging 1.35 ± 0.07 and 0.72 ± 0.10 circ/sec in the patients with normal and abnormal ventricular performance, respectively ( P < 0.001). Peak wall tension did not differ significantly between the two patient groups, averaging 231.4 ± 15.7 and 273.3 ± 16.4 g/cm in the patients with normal and abnormal ventricular function, respectively. Peak instantaneous power was higher in the normal compared to the abnormal group, averaging 8.39 ± 0.83 and 5.91 ± 0.60 kg-cm/sec per cm of circumference, respectively ( P < 0.05). It is concluded that a three-dimensional construct of left ventricular circumferential velocity, tension, and length during ejection is readily obtainable during diagnostic cardiac catheterization and provides a sensitive and comprehensive description of LV myocardial function in man.

Quantitative angiographic analysis of the left ventricle in patients with isolated rheumatic mitral stenosis

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Left ventricular performance after myocardial infarction assessed by radioisotope angiocardiography

Radioisotope angiocardiography was performed by peripheral venous or pulmonary arterial injection of 99m Tc pertechnetate in 64 patients with acute myocardial infarction. End-diastolic volume determined with this technic averaged 101 ± 7 (± sem ) ml/m 2 and was elevated (> 90 ml/m 2 ) in 47 patients. Initial ejection fraction (EF) averaged 0.38 ± 0.03 and was reduced (<0.52) in 58 patients. The extent of diameter shortening at the minor left ventricular equator determined from the isotope angiocardiograms was depressed in 51 patients, a reduction which was not consistently related to the site of infarction determined electrocardiographically. In 53 survivors EF averaged 0.40 ± 0.02, compared to 0.26 ± 0.07 ( P < 0.05) in 11 patients who died within 1 month. EF correlated inversely with infarct size estimated by analysis of serial changes in serum CPK activity (r = 0.71, n = 42). Of the 64 patients with acute infarction, 47 exhibited abnormal wall motion detectable by the radionuclide technic and confirmed by radarkymography. Serial radioisotope angiocardiograms (6 hours-1 month) showed improvement of cardiac function in 30 of 55 patients, with no change in 12, and deterioration in 13 patients. Results obtained indicate that radioisotope angiocardiography performed by peripheral intravenous injection of 99m Tc pertechnetate can be performed safely, rapidly, and serially without hemodynamic perturbation to assess left ventricular performance in patients critically ill with acute myocardial infarction.

Comparison of ultrasound and cineangiographic measurements of the mean rate of circumferential fiber shortening in man

It has been shown that cineangiographic measurement of the mean rate of circumferential fiber shortening (mean V CF ) at the minor left ventricular equator is a reliable method for evaluating the mechanics of cardiac performance. Since fiber shortening can be derived from the echocardiogram, we sought to validate the measurement of mean V CF by this noninvasive technic in patients studied by both methods. In 15 patients considered to have normal left ventricular function, the average mean V CF determined by ultrasound was 1.29 ± 0.23 circumferences/sec, while in the 13 patients with reduced left ventricular performance this value was 0.75 ± 0.16 circumferences/sec ( P < 0.001). Values of mean V CF by the two technics were similar and separated normal from abnormal ventricular function in 27 of 28 patients. The average mean velocity of posterior wall motion was 4.7 ± 1.1 cm/sec in normal patients and 3.9 ± 1.3 cm/sec in abnormals, but posterior wall velocities did not correlate well with either ultrasound or cineangiographic determinations of mean V CF . Ejection fraction calculated from ultrasound measurements correlated significantly with the ejection fraction calculated by cineangiography (r = 0.83, P < 0.0001). The ejection fraction and mean V CF , as determined by ultrasound in the 28 patients, correlated well (r = 0.92, P < 0.0001), but there were six discordant points.

From these studies we conclude that the ultrasound determination of mean V CF is a valid method for distinguishing normal from abnormal myocardial performance of the left ventricle. These data also support the use of ultrasound in determining ejection fraction. Estimation of posterior wall velocity, although perhaps useful in the serial study of the same patient, seems limited in its ability to assess cardiac performance accurately.

Cardiovascular effects of weight reduction

Weight reduction programs usually improve the exercise capacity of patients with chronic exogenous obesity. However, the reversibility of left ventricular hypertrophy and dysfunction associated with obesity is unknown. Accordingly, an analysis was made of hemodynamic data obtained by cardiac catheterization and standard chest roentgenograms in nine markedly obese patients before and after weight loss of 39 to 84 kg (24 to 55% of control weight) over periods of 4 to 34 months. In each case body oxygen uptake (360 to 297 ml/min), blood volume (7.8 to 6.1 liters), cardiac output (7.9 to 6.2 liters/min), and arteriovenous oxygen difference (4.6 to 4.0 vol. %) were significantly reduced after weight loss. Systemic arterial pressure declined (102 to 87 mm Hg) while systemic vascular resistance changed insignificantly (1,067 to 1,141 dynes-sec-cm -5 ). In seven subjects comparable chest roentgenograms before and after weight reduction revealed decrease in the cardiothoracic ratio, suggesting a reduction in left ventricular dimensions. These results have been interpreted as indicating that the circulatory effects of gross obesity are largely reversible with weight loss. Despite reductions in left ventricular stroke work, stroke volume, and cavity size at rest, the average left ventricular filling pressure rose with exercise to a comparable and abnormal level (20 mm Hg) both before and after weight loss. Thus, evidence of left ventricular dysfunction persisted, suggesting that myocardial hypertrophy and reduced ventricular compliance did not regress significantly with weight loss over periods as long as 3 years.

Myocardial perfusion imaging with radioactive-labeled particles injected directly into the coronary circulation of patients with coronary artery disease

Macroaggregated serum albumin (MAA) particles labeled with 131 iodine ( 131 I) or similar particles-labeled with 99m technetium ( 99m Tc) or both types were injected directly into the coronary circulation of 29 patients at the time of conventional coronary arteriography. Radionuclide images of the distribution of these small (10-60 µ) biodegradable particles in the small vessels of the heart wall were made with a commercial Anger-type scintillation camera in much the same way as routine pulmonary perfusion scans are made. The resulting images depicted the relative regional distribution of blood flow to the myocardium in these patients suspected of having coronary artery disease. The myocardial perfusion images were of good quality and allowed gross assessment of perfusion by way of each major coronary artery. This was done by injecting 99m Tc-labeled particles into the left coronary artery and 131 I-MAA into the right coronary artery through the coronary artery catheter. Separate or composite images of the relative small vessel perfusion via each vessel injected were obtained by electronic pulse-height discrimination. No untoward reactions followed the intracoronary injection of the labeled particles. From our preliminary experience, we conclude that myocardial perfusion imaging in conjunction with coronary arteriography may prove to be a valuable diagnostic tool in the evaluation of the regional vascular supply to the heart in patients with coronary artery disease.