摘要:

This is an updated and expanded planning and optimal resource guideline for diagnostic examinations of the cardiovascular system. Catheterization-angiographic laboratories are described and detailed specifications given for radiologic and physiologic equipment. Case loads for maintaining safe and effective performance are recommended and complication rates discussed. An optimal location for the laboratory is defined and the status of affiliated laboratories reviewed. Professional staff qualifications, relationships and requirements are enumerated and recommendations are made for organization and administration of the services. There is a protocol for electrical safety and radiation protection and a data base for assessing case loads in hospitals within a community or region. This statement also defines optimal facility and equipment criteria for conventional chest x-rays and radiologic equipment requirements for cardiovascular surgical operating rooms and intensive care unit

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Mitral valve motion and pressure correlates of the Austin Flint murmur (AFM) were investigated in nine patients with aortic regurgitation using high fidelity catheter tip micromanometers and the mitral valve echocardiogram (MVE). External phonocardiography demonstrated a mid-diastolic murmur (MDM) in eight subjects and a presystolic murmur (PSM) in five. Maximum intensity of both AFM components was found in the left ventricular (LV) inflow tract; the murmur was not recordable in the left atrium (LA). In two patients, an apparent AFM was recorded in the intracardiac phonocardiogram when absent externally. Only one subject had a significant late diastolic “reversed” or LV to LA gradient; in this patient, presystolic mitral regurgitation was shown angiographically but no PSM was present and MVE revealed absence of atriogenic mitral valve re-opening. In two subjects, a PSM disappeared from the external phono when a “reversed” gradient occurred during the diastolic pause following a ventricular premature systole; this LV to LA gradient was associated with diastolic mitral regurgitation recordable in the left atrial phono. In two patients, LV inflow phono showed the MDM to begin 80–120 msec after the aortic second sound and during the D to E phase of the MVE. The rate of early diastolic mitral valve closure in patients (152±24 mm/sec) was not significantly different from 13 normals (232 i 30 mm/sec). With regard to the genesis of the AFM, the present study concludes: 1) diastolic mitral regurgitation plays no role, and 2) antegrade mitral valve flow is required but simultaneous retrograde aortic flow may also be necessary.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Thirteen episodes of concealed junctional ectopic impulses (JEI) in ten patients are described. In nine patients the JEI manifested as isolated automatic impulses and in one as a parasystolic junctional tachycardia. In addition to the previously described unexpected prolongation of the P-R, Type I and Type II A-V block, the following phenomena were recorded: 1) marked, greater than 400 msec, and persistent prolongation of the P-R interval, 2) striking changes in the duration of the P-R with an occasional sequence of R-P and P-R intervals simulating “supernormal” A-V conduction, 3) unexpected variation of the junctional escape interval explained by junctional parasystole with entrance block, 4) postponed conpensatory pause, 5) concealed junctional discharge with reciprocation.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

To estimate the effect of distance between the electrode and the signal source on the amplitude of the His bundle electrogram (HBE) recorded during open heart surgery, a specially designed probe, containing six pairs of closely spaced (1 mm) electrodes was placed on the endocardial surface of the right atrium such that each electrode pair was parallel to the course of the His bundle. The amplitude of the HBE recorded through electrodes closest to the His bundle ranged from 0.76 to 3.44 mV, at 1 mm from 0.38 to 1.13 mV, at 2 mm from 0.27 to 0.86 mV, and at 3 mm from 0.2 to 0.44 mV. Maximal amplitude of HBE decreased by 57% at I mm, 73% at 2 mm, and 82% at 3 mm. The percent decrease was initially rapid, then declined more slowly at distances greater than 1 mm, resembling in form data obtained previously in animal studies by different techniques.Since the maximum HBE was greater than 1.0 mV in nine of 11 patients, and equal to or greater than 1.0 mV in only two of 11 patients at 1 mm, and less than 1.0 mV in all patients 2.0 mm from the maximal HBE, the anatomic location of the His bundle can be estimated from HBE amplitude. Intracardiac electrograms, recorded through closely spaced bipolar electrodes during open heart surgery, afford clinically useful precision in locating the specialized conduction tissue of the heart.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Frank lead vectorcardiograms (VCG) from four carefully selected patient subgroups (226 patients) were analyzed to develop optimal criteria for the diagnosis of anterior myocardial infarction. Specificity was evaluated using 100 healthy volunteers under age 30 and 80 patients with normal left ventriculogram and normal coronary arteriograms. Sensitivity was determined using 25 patients with evolutionary ST-T wave changes (V1 2), and LDH and CPK isoenzyme evidence of acute myocardial infarction; and 21 patients with anterior wall akinesia or dyskinesia and > 70% occlusion of the left anterior descending coronary artery. Patients with VCG evidence of bundle branch block, left or right ventricular hypertrophy were excluded.The criterion for the diagnosis of anterior myocardial infarction which was found to give the highest sensitivity with .95% specificity was: initial anterior QRS forces must not exceed 0.1 mV in maximal anterior amplitude and also must not exceed 24 msec in duration. The performance of this proposed criterion was then tested using four similarly defined patient subgroups consisting of a total of 222 patients. The incidence of false positive diagnosis in these test subgroups was < 1% with a sensitivity of >95%. The overall performance of the proposed criterion was found to be significantly superior to both the widely accepted VCG and ECG criteria for anterior myocardial infarction. Thus, this quantitative criterion using both time and duration of initial anterior forces is both a highly specific and a sensitive indicator of anterior myocardial infarction.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Vectorcardiograms (VCG) from a consecutive group of 77 patients with significant aortic valve disease were analyzed. All of the patients had complete left and right heart catheterization with normal coronary arteriograms and normal left ventricular contraction. Thirty-five (46%) patients met VCG criteria for anterior myocardial infarction (AMI-35%) and/or inferior myocardial infarction (IMI-14%). This was a significant increase in false positive diagnosis for both criteria compared to a group of 200 normal volunteers under age 30 and 100 patients with normal hearts by cardiac catheterization (P < 0.01). It was found that if the VCG diagnosis of myocardial infarction was deferred when the maximal transverse plane magnitude was >1.8 mV, the incidence of AMI false positive diagnosis decreased to 3% and the incidence of IMI false positive diagnosis decreased to 1%. The same rule was applied to the aortic valve disease cohort, a group of 124 patients with documented AMI and a group of 158 patients with IMI. This decreased the sensitivity of the AMI criteria from 93 to 83% and of the IMI criteria from 85 to 77%. The increase in average performance was statistically significant for the AMI criteria (P < 0.05) but not for the IMI criteria.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

In a rate-stable pacemaker, pacemaker rate reflects battery voltage level and should remain constant or be slightly depleted with time in a linear fashion until failure occurs. Linear regression techniques are therefore particularly suited to the analysis of pacemaker rate data. Data on model 8114/8114A Starr-Edwards pacemakers followed at the University of Oregon Health Sciences Center were studied. For a given pacemaker both the slope of the regression line and the standard deviation about the regression line are proportional to the original rate. Natural indices of rate depletion and rate stability for each pacemaker can therefore be calculated by dividing the slope and the standard deviation, respectively, by the intercept of the corresponding regression line. This model pacemaker has a small average standard deviation so that significant variations from the line of regression, indicating impending pulse generator failure, can be detected in spite of random fluctuations. Emergency and prophylactic replacements can therefore be kept to a minimum so that pulse generator lifetime is maximized. Success in extending pulse generator longevity can be measured by actuarial techniques, which show this pacemaker to have a median battery depletion time of 38 months and a median replacement time of 35 months.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Twenty-four patients in the pediatric age range who underwent implantation of a cardiac pacemaker for treatment of complete atrioventricular (A-V) block were followed for: an average of five years (range 1–12 years). The etiology of the A-V block was surgical in 13 cases, congenital in nine, and acquired in two. Twenty patients had symptoms of cerebrovascular insufficiency and four had congestive heart failure. To date, 18 of the 24 patients studied are alive and well. Death occurred in six patients, five of whom had complex congenital heart defects, and one of whom had Refsum's disease. Death probably was caused by complete heart block despite pacemaker treatment in four patients, and congestive heart failure in two. In 18 of the 24 children with disabling complete A-V block, pacemaker therapy provided relief of symptoms and prolonged life.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

The effects of abnormal ventricular activation upon the contractile pattern of the ventricles in patients with the Wolff-Parkinson-White syndrome (WPW) remain uncertain. Therefore we compared the motion of the anterior right ventricular wall (RV), the interventricular septum (IVS), and left ventricular posterior wall (LVPW) on echogram in nine patients with WPW and one patient with a coronary sinus pacemaker (CSP) to 20 normal subjects. Normal subjects manifested posterior RV motion which began and reached maximal excursion at 175 and 366 msec (group mean), respectively, after the onset of the QRS complex; posterior movement of the IVS which started and peaked at 90 and 350 msec, respectively; and anterior contraction of the LVPW which began and peaked at 159 and 406 msec, respectively. Five of seven patients with Type A WPW demonstrated a localized area of premature contraction of the LVPW occurring during the initial 100 msec interval following the onset of the QRS complex which was accompanied by paradoxic anterior motion of the IVS. Thereby in Type A patients initial and maximal posterior motion of the IVS occurred later, 230 (P ⩽ 0.001) and 400 (P⩽ 0.05) msec, and anterior motion of the LVPW occurred earlier, 75 (P< 0.001) and 367 (P< 0.05) msec as compared to normal. The amplitude and duration of early contraction could be related to the prominence of the delta wave during atrial pacing. Similar premature contraction was also observed in the patient with CSP during paced beats. One Type B WPW patient exhibited abnormal IVS motion while the additional patient manifested premature LVPW contraction similar to that seen in Type A patients. The contractile pattern of the right ventricular anterior wall was recorded in five of seven Type A Wolff-Parkinson-White patients and manifested prolongation of the interval from the onset of the QRS complex to the initial posterior movement (group mean 234 msec,P< 0.05) as compared to normal. Thus echocardiography can be used to confirm the diagnosis and to improve understanding of the pathophysiology of the Wolff-Parkinson-White syndrome.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID