Kenneth B. Desser

Doppler Ultrasound in Cardiology: Physical Principles and Clinical Applications

Hatle and Angelsens book Doppler Ultrasound in Cardiology describes the physical principles and some clinical applications of both pulsed and continuous signals. Of the eight chapters, five represent technical explanations of the technique, including concepts and equations that require knowledge of advanced physics and mathematics. The authors, recognizing this necessary scope of comprehension, outline an introductory reading path in the preface, which is unorthodox and complicated. Two chapters explain the advantages and limitations of Doppler ultrasound in the assessment and evaluation of normal heart function and selected intracardiac disorders. During the past three years, major advances have been made in cardiovascular diagnosis by means of combined M-mode or two-dimensional echocardiography and Doppler wave analysis. It is unfortunate that the authors did not include these methods, and, in fact, they dismiss such utility in the introduction. Major areas of application such as carotid or peripheral vascular disease are not discussed at

Accelerated Ventricular Rhythm and Cocaine Abuse

Excerpt Cocaine has the peculiar quality of being both a local anesthetic and a sympathomimetic agent with powerful central nervous-system stimulant effects. In small doses cocaine can slow the hea...

Simultaneous left ventricular echocardiography and aortic blood velocity during rapid right ventricular pacing in man.

AbstractLeft ventricular echocardiograms and phasic instantaneous Doppler aortic blood velocities were simultaneously recorded during short paroxysms of rapid right ventricular pacing in 20 conscious subjects. Right ventricular pacing at rates of 100, 120, 140, 160 and 180/min produced stepwise reductions of mean estimates for diastolic (D) and systolic (S) left ventricular internal dimensions (LVID) along with a diminution of aortic blood velocity. Mean (&OV0398; ± 1 standard deviation) per cent decline of LVID-D, LVID-S and peak aortic blood velocities for the study group ranged from 8.9 ± 6.1, 8.5 ± 5.7 and 13.7 ± 7.7 at 100 beats/min to 29.3 ± 10.6, 25.2 ± 10.5 and 55.2 ± 13.1 at 180 beats/min, respectively. When LVID-D, LVID-S, and aortic blood velocity x % reductions were plotted for all heart rates there was a high degree of positive correlation (r = 0.99). Two types of abnormal septal motion were observed during rapid pacing: Type I—paradoxical septal motion at all pacing rates (n = 7, 6/7 with left coronary artery disease); Type II—hypokinetic septal motion at lower pacing rates with flat or paradoxical motion at rates > 140/min (n = 13, 10/13 with normal coronary arteries). It is concluded that short episodes of rapid right ventricular pacing result in reduced LVID and abnormal septal motion with the latter possibly related to septal ischemia. Such study provides insight into the untoward influence of rapid ventricular rhythms on cardiac performance.

Bidirectional blood flow velocity in the cardiac chambers and great vessels studied with the Doppler ultrasonic flowmeter

Abstract Utilizing the bidirectional Doppler flowmeter catheter system, phasic forward and reverse flow velocity was measured in the cardiac chambers and great vessels of man. Recordings of right atrial, right ventricular and aortic flow velocity are characterized by a small reverse flow velocity component, usually occurring during early diastole, followed by a large forward systolic wave. Blood flow velocity in the left ventricular outflow tract and pulmonary artery is forward with negligible or no reverse flow. Ventricular extrasystoles and ventricular tachycardia result in diminished systolic and enhanced retrograde aortic and right ventricular flow velocity, possibly based on valvular incompetence. Aortic regurgitation and tricuspid insufficiency can be identified by their characteristic diastolic and systolic reverse flow velocity patterns. Patients with an increase in right atrial pressure, regardless of its etiology, manifest significant reverse flow velocity toward the caval system. We conclude that this technic is a valuable method for measuring bidirectional flow velocity under normal and pathologic conditions.

The Frank vectorcardiogram in left posterior hemiblock

Summary The abnormalities of the Frank vectorcardiogramare described in 18 patients with left posterior hemiblock. It is demonstrated that the sequence of ventricular activation is altered in patients with left posterior hemiblock, especially at the time of inscription of the 10 to 20 msec vectors. The most evident vectorcardiographic signs for the diagnosis of left posterior hemiblock are: (1) maximum QRS deflection vector in the frontal plane directed at or beyond +100 degrees, (2) superiorly directed 10 to 20 msec QRS vectors, (3) clockwise rotation of the QRS loop in the frontal plane and (4) delayed inscription of the 60 to 100 msec vectors.

Coxsackie B5 heart disease. Demonstration of inferolateral wall myocardial necrosis.

A case of Coxsackie B5 viral myopericarditis is presented in which the diagnosis of inferolateral wall myocardial necrosis was made on the basis of specific cardiac enzyme changes and radionuclide myocardial imaging. This localized damage may have resulted from coronary arteritis with resulting infarction or necrosis secondary to preferential viral involvement of the inferolateral wall of the myocardium. Hepatitis and cerebral embolism complicated the case, with the latter suggesting endocardial disease.

Relief of angina pectoris in patients with occluded coronary bypass grafts

Thirty-two patients from a larger series of subjects undergoing routine postoperative evaluation of the aortocoronary saphenous bypass graft procedure were found to have one (20 patients) or all (12 patients) of the implanted grafts totally occluded. Such occlusion occurred in association with persistent postoperative subjective improvement manifested by a significant diminution or complete disappearance of angina pectoris. Postoperative myocardial infarction was documented in only seven cases, and the possibility of successful partial revascularization could be logically applied to only 20 of these 32 patients. Other suggested mechanisms for relief of angina pectoris in this setting are mentioned, although none is scientifically proved. It is concluded that (1) the marked subjective improvement documented in this population does not universally correlate with anatomic success and that (2) a diminution in the degree of angina pectoris cannot be clinically applied as a reliable indicator of postoperative graft patency.

Right sinus of Valsalva-right atrial fistula secondary to nonpenetrating chest trauma: a case report with description of noninvasive diagnostic features.

A sinus of Valsalva-right atrial fistula secondary to nonpenetrating chest trauma is described. Echocardiogrpahy demonstrated diastolic fluttering of the anterior tricuspid valve, suggesting a left-to-right shunt at the level of the right atrium. External jugular venous pulse tracings revealed large alpha waves and attenuation of the y descent. Cardiac catheterization disclosed a fistulous communication between the right sinus of Valsalva and right atrium. After surgical repair of the fistula, the ultrasonic recording and external pulse tracing reverted to normal. We believe this is the first description of such a shunt after blunt thoracic trauma.

The Valsalva Maneuver and Coronary Arterial Blood Flow Velocity: Studies in Man

Abstract Effects of the Valsalva maneuver on left coronary blood flow velocity were assessed in 15 patients with the Doppler catheter tip flowmeter. Straining against a closed glottis induced a dec...

How many electrocardiographic leads are required for exercise treadmill tests

Forty-four consecutive patients who had perfusion defects on thallium-201 scanning and positive exercise treadmill tests were prospectively studied. Thirty-eight (86%) subjects had diagnostic ST segment changes in lead V5, 37 (84%) in lead V4, and 44 (100%) in either lead V4, V5 or both. Thirty patients had ST segment changes in the inferior leads, 20 in lead aVR, and only four in lead I and/or aVL. All of these latter subjects had diagnostic ST segments in lead V4 and/or V5. It is concluded that: combined electrocardiographic leads V4 and V5 detect the vast majority of ischemic changes during exercise treadmill testing, regardless of the site of perfusion defects detected by thallium-201 scanning; and monitoring the inferior and lateral leads rarely provides more diagnostic information.