Lakier Jb

Radiographic pulmonary congestion in end-stage congestive heart failure.

Abstract Chest radiography is considered an accurate technique for evaluating the presence and degree of congestive heart failure1 (CHF). Radiographic evidence of redistribution of pulmonary blood flow and interstitial and alveolar edema is an established indicator of pulmonary artery wedge pressure in both acute and chronic forms of CHF.2 It is believed that the absence of these radiographic findings is inconsistent with severe CHF and, specifically, elevations of pulmonary artery wedge pressure.3–5 Much work describing the utility of chest radiography in the diagnosis and management of patients with CHF was carried out before the advent of potent diuretics and vasodilator agents.6 Currently, many treated patients with end-stage CHF do not have clinical congestion and may die suddenly despite apparent hemodynamic compensation.7,8 This report examines the chest radiographic abnormalities observed in patients with chronic severe CHF and marked elevation of pulmonary artery wedge pressure.

Porcine xenograft valves. Long-term (60-89-month) follow-up.

An analysis of 211 patients who had porcine xenograft valve replacements at Henry Ford Hospital between October 1971 and March 1974, was accomplished, with 100% follow-up. The follow-up period extended from 60–89 months after implantation. One hundred sixty-seven patients with 192 valves survived the perioperative period and were subjected to life table analysis. Hemodynamically significant porcine xenograft degeneration that required reoperation occurred in 18 patients, two of whom had infective endocarditis. Only four valves failed within 48 months of surgery. Ten of 42 (23.8%) patients with isolated aortic valve replacement and eight of 102 patients (7.8%) patients with isolated mitral valve replacement required reoperation (p < 0.01). In patients under 25 years of age, six of nine surviving patients had repeat operations. Our data indicate that porcine xenograft degeneration is related to the duration of implantation and the age of the patient at the time implantation was performed. In addition, porcine xenograft valves in the aortic position are more likely to degenerate than are those in the mitral position.

Frequency of the first heart sound in the assessment of stiffening of mitral bioprosthetic valves.

SUMMARY The frequency spectrum of the first heart sound (S1) was measured noninvasively in 54 patients with porcine bioprosthetic valves inserted in the mitral position. Phonocardiograms were recorded on magnetic tape on line with a signal processor with which the frequency spectrum and peak frequency of S1 were determined. In 19 patients with normal natural mitral valves, the apparent peak frequency within the range of measured frequencies of S1 was 46 ± 2 Hz (mean ± SEM). In 11 patients with porcine bioprosthetic valves implanted in the mitral position for < 1½ years, the apparent peak frequency of S1 was 43 ± 3 Hz, which was not significantly different from S1 in patients with normal mitral valves. However, in 33 patients with porcine bioprosthetic valves in place 5–7 years, the apparent peak frequency of S1 was higher, 67 ± 2 Hz (p < 0.001). In patients in whom the porcine bioprosthetic valve was implanted 5 years or longer, the frequency spectrum of S1 showed a greater proportion of sound energy at frequencies between 50–200 Hz compared with patients in whom the prosthetic valve was implanted 1½ years or less. Changes of the frequency of S1 in these patients may be a manifestation of stiffening of the valve as a result of early degenerative changes.

Risk identification at the time of admission to coronary care unit in patients with suspected myocardial infarction

The in-hospital clinical course was evaluated in 2,162 consecutive patients admitted with a diagnosis of suspected myocardial infarction. Of these, 1609 patients were considered to be in the high-risk group, based on the presence of 16 clinical criteria present at the time of admission. The remaining 553 patients were classified as low risk. The overall rate of complications in the coronary care unit was greater in the high-risk group, 64%, compared to 26% in the low-risk group (p less than 0.001). Similarly life-threatening events (occurrence or recurrence of ventricular fibrillation, sustained ventricular tachycardia, complete heart block, asystole, or cardiogenic shock) were more common in the high risk-group compared to the low-risk group, 11% and 0.9%, respectively (p less than 0.001). The high-risk group required significantly more interventions, such as electrical cardioversion, temporary pacing, pulmonary artery catheterization, and intraaortic balloon counterpulsation, compared to the low-risk group (20% vs 2%, respectively; p less than 0.001). Myocardial infarction was confirmed in 892 patients in the high-risk group (55%) compared to 90 (16%) in the low-risk group (p less than 0.001). The coronary care unit mortality rate was greater in the high-risk group compared to the low-risk group (8.2% vs 0.4%, respectively; p less than 0.0002). It is concluded that based on readily available clinical criteria at the time of admission, a subgroup of patients at low risk for developing life-threatening complications requiring coronary care unit interventions can be identified and admitted directly to an intermediate-care unit.

Mechanism of a musical systolic murmur caused by a degenerated porcine bioprosthetic valve

The cause of a musical (cooing) murmur produced by a degenerated bioprosthetic valve in the mitral position was investigated. Spectral analysis of the murmur recorded at the chest wall at the site of the maximum palpable impulse showed virtually all sound in a narrow frequency band around the dominant frequency of 158 hertz. The same valve, surgically removed and mounted in the mitral position in a pulse duplicating system, produced an audible musical murmur detected by a phonocatheter in the atrial chamber. Nearly all of the sound-pressure occurred in a narrow band of frequency around 145 hertz. High speed motion pictures (500 frames/s) showed systolic flutter of a flail leaflet. The frequency of this leaflet flutter was 142 hertz. Hot film anemometry showed minimal turbulence, all located near the margin of the regurgitant leaflet. The intensity of the murmur was unrelated to the intensity of turbulence. A second degenerated bioprosthetic valve that produced in vivo a typical blowing holosystolic mitral regurgitant murmur produced in vitro a murmur with a broad range of frequencies (20 to 500 hertz). With this valve, the intensity of the murmur was related to the intensity of the turbulence. Motion pictures showed no leaflet flutter. Flutter of an insufficient valve leaflet causing uniform and periodic high frequency fluctuating pressures therefore appeared to be the cause of the musical quality of the systolic murmur in a degenerated bioprosthetic valve.

Origin and clinical relevance of musical murmurs

Although our observations are limited to studies performed on a degenerated bioprosthetic valve that produced a musical murmur, we believe that they can be applied to musical murmurs caused by abnormal natural valves. Several points regarding the characteristics of musical murmurs have been clarified. A musical murmur results from a uniform periodic vibration of a cardiac structure. A non-musical murmur results from turbulent blood flow which initiates random vibrations of adjacent structures. The broad spectrum of frequency of a non-musical murmur reflects the broad range of random fluctuations of blood velocity that characterizes turbulent blood flow. The frequency, amplitude, and time of occurrence during systole or diastole of a musical murmur are dependent upon the hemodynamics in the vicinity of the vibrating structure. Variability of all of these characteristics of the murmur, therefore, may be expected. Musical murmurs may have a purer tone at a site distal to the source than close to the source. This may reflect a superimposition of a broad spectrum of noise due to turbulence close to the valve. With distance from the valve, turbulence attenuates more than the sound-pressure fluctuations which are due to the uniform vibrations of the valve. A pure tone, uncontaminated by this broad spectrum of noise due to turbulence, therefore, is heard at some distance from the valve.