Comparison of fasting and postprandial plasma lipoproteins in subjects with and without coronary heart disease.

Plasma lipoprotein levels, including remnant-like particle (RLP) cholesterol and RLP triglycerides, were assessed in fasting (12 hours) and postprandial (PP) (4 hours after a fat-rich meal) states in 88 patients with coronary heart disease (CHD) and 88 controls. All lipoproteins were assessed by direct methods. We hypothesized that patients with CHD would have greater percent increases in their triglyceride levels, RLP cholesterol, and RLP triglycerides, in response to a fat-rich meal. In the fasting state, triglycerides, RLP cholesterol, RLP triglycerides, and low-density lipoprotein (LDL) cholesterol levels were all significantly higher in cases versus controls by 51%, 35%, 39%, and 40%, respectively. These levels were 57%, 37%, 64%, and 37% higher in the PP state, respectively. Mean high-density lipoprotein (HDL) cholesterol values were 27% lower in cases in both the fasting and PP states. After eating, triglycerides, RLP cholesterol, and RLP triglycerides increased 64%, 71%, and 290% in controls, respectively, whereas in cases these levels increased by 71%, 94%, and 340%, respectively (all p <0.0001). Percent increases in the PP state were not significantly different in cases versus controls. Following the fat-rich meal, LDL and HDL cholesterol decreased by 5% and 4% in controls, and by 7% and 6% in patients, with no significant difference in percent changes between groups. Fasting values correlated very highly with PP values for all parameters (all p <0.0001). Our data indicate that although patients with CHD have higher fasting and PP levels of triglycerides, RLP cholesterol, and RLP triglycerides than controls, the response (percent increase) to a fat-rich meal is comparable in both groups. Thus, a feeding challenge is not essential for assessment of these lipoproteins. Moreover, it is not necessary to obtain a fasting sample to assess direct LDL and HDL cholesterol.

High-intensity strength training of patients enrolled in an outpatient cardiac rehabilitation program.

PURPOSE: This randomized controlled study assessed whether adding a program of high-intensity strength training (80% of maximum) to an outpatient cardiac rehabilitation program would be a safe and effective means of improving muscle strength and body composition. METHODS: Thirty-eight cardiac patient volunteers (29 men and 9 women) were randomized to either high-intensity strength training or flexibility training added concurrently to a 12-week outpatient cardiac rehabilitation aerobic exercise program. Muscle strength, local muscle endurance, joint flexibility, maximum treadmill tolerance time, and body composition were measured before and after completion of the training. RESULTS: The strength-trained patients (n = 18) had greater increases in mean strength (90 +/- 19% versus 9 +/- 4%, P < 0.0001) and local muscle endurance (20 versus 6 times, P < 0.0001), and decreases in mean perceived exertion for lifting the initial one repetition maximum load (11 +/- 1 versus 15 +/- 1, P < 0.0001) when compared with flexibility-trained patients (n = 16). The strength group lost more body fat (2.8 +/- 2.0 versus 1.3 +/- 2.0 kg, P < 0.01), tended to gain more lean tissue (1.5 +/- 2.3 versus 0.5 +/- 1.2 kg, P < 0.10), and had greater improvements in treadmill time (2.3 +/- 1.3 versus 1.2 +/- 1.0 minute, P < 0.02) than did the flexibility group. Improvements in joint flexibility were similar for each group. None of the subjects had evidence of cardiac ischemia or arrhythmia during the training sessions. CONCLUSIONS: Medically supervised high-intensity strength training is well tolerated when added to the aerobic training of cardiac rehabilitation programs and allows patients to aggressively gain the strength and endurance they will need to complete daily living tasks at lower perceived efforts. Strength training also reduces cardiac risk factors by improving body composition and maximum treadmill exercise time.

Effects of high-intensity strength training on quality-of-life parameters in cardiac rehabilitation patients.

Cardiac rehabilitation programs have not consistently been shown to improve the psychological well being of their patients. In our study of 38 cardiac patients (29 men and 9 women), a variety of quality-of-life parameters were assessed before and after they completed either 12 weeks of high-intensity strength training or flexibility training added to their outpatient cardiac rehabilitation aerobic exercise program. The strength-trained patients increased their self-efficacy scores for lifting (29% vs 4%, p <0.05), push-ups (65% vs. 17%, p <0.01), climbing (36% vs 0%, p <0.001), and jogging (100% vs -9%, p <0.001), when compared with the flexibility-trained patients. The strength group also had greater improvements in Profile of Mood States dimensions: total mood disturbance (123% vs 18%, p <0.05), depression/dejection (73% vs 15%, p <0.05), and fatigue/inertia (42% vs 3% p <0.05), than did the flexibility group. The Medical Outcome Survey Short Form 36 role emotional health domain scores were significantly improved in the strength group when compared with the flexibility group (64% vs 0%, p <0.05), and the role limitation scores improved in both groups. Increases in strength were associated with enhanced self efficacy and improved mood and well-being scores (n = 34, r = 0.30 to 0.53, p <0.05). High-intensity strength training added to a cardiac rehabilitation program of selected patients leads to improvements in quality-of-life parameters. These data, in conjunction with improvements in strength, strongly support the value of adding high-intensity strength training to cardiac rehabilitation programs.

A new Doppler-echo method to quantify regurgitant volume.

An in vitro technique using color flow imaging and continuous wave Doppler was developed to measure the initial regurgitant flow jet diameter and velocity integral to yield the parameters for a volume calculation. Jets were produced by volume-controlled injection through tubes of various diameters (1.3, 1.9, 2.8, and 3.5 mm) to deliver volumes from 1 to 7 ml over 100 to 300 msec at pressures from 40 to 200 mm Hg. One hundred forty-five samples were obtained. Flow jet diameter consistently overestimated tube diameter by 2 mm when injected volume was 1.5 to 7 ml and by 1.5 mm when injected volume was less than 1.5 ml. This offset was stable with various transducers (2.5, 3.5, 5.0 MHz) at normal gain setting (just under noise). Therefore, corrected flow jet diameter (FJD) = FJD - 2 mm, and Doppler volume = corrected flow jet area x velocity integral. A range of injectates from 1.1 to 7 ml generated Doppler volume of 1.0 to 8.2 ml. The relation between Doppler volume (DV) and injected volume (IV) was DV = 1.079 IV - 0.22, r2 = 0.945, p less than 0.01. This relation was not altered by tube diameter. Thus a method combining color flow imaging and continuous wave Doppler provides a reliable and accurate measure of in vitro flow volume.

Late perforation by pacemaker catheter loop in the neck: a preventable complication of the external jugular approach.

The external jugular vein is a less favored but still useful route for insertion of cardiac pacemaker catheters. When this approach is used, gradual descent of the pulse-generator in the subcutaneous tissue of the chest wall may produce sharp angulation of the catheter as it enters the vein. This may result, many months later, in pressure necrosis of the overlying skin. Techniques aimed at preventing such pulse-generator descent should obviate this complication.

Pacemaker runaway following intermittent output failure.

A case with a mixed pattern of pacemaker failure is presented. "Runaway" pacemaker with ventricular capture at 250 beats per minute occurred three days after the development of syncope associated with intermittent loss of pacing artifact. Presumed protection by placement of a temporary pacemaker upon admission was unfounded. This case argues for rapid diagnosis of pacemaker failure, followed by prompt surgical exploration and repair of the pacing system.

The echocardiogram of the anterior leaflet of the mitral valve. Correlation with hemodynamic and cineroentgenographic studies in dogs.

The echocardiogram of the anterior leaflet of the mitral valve (ECHO) was compared to hemodynamic and cineroentgenographic data to evaluate its accuracy in timing mitral valve (MV) opening and closure, and to validate it as an indicator of MV motion. The ECHO, high speed cineroentgenography at 250 frames/sec, and/or measurement of intracardiac pressures allowed accurate timing of the events of MV motion in dogs on right heart bypass. The intersection of left ventricular and left atrial pressures in early diastole preceded the onset of rapid anterior motion of ECHO (D' point) by 17 to 33 plus or minus 7.6 msec; r equals 0.98. The onset of left ventricular systole occurred before the termination of final rapid posterior motion of the ECHO in end diastole (Co point) by 25 plus or minus 10 msec; r equals 0.96. Radiopaque clips were attached to the free edges of both leaflets of the MV. Cineroentgenographically determined plots of clip distance from the ultrasound transducer were morphologically similar to the simultaneously recorded ECHO. A delay of 23 plus or minus 3 (0 to 40) msec was observed in the ECHO peaks of diastolic anterior excursion compared to clip motion. Contrast medium advances beyond the free edges of MV leaflets mixing with left ventricular blood 43 plus or minus 3 msec after initial separation. These cineroentgenographic studies elucidate nonuniformity of leaflet motion responsible for ECHO delays. Thus, ECHO D' and Co correlate well with hemodynamic indicators of MV opening and closure. However, ECHO motion, although qualitatively similar, is unpredictably delayed compared to cineroentgenography of clips on the MV free edge. Since the ECHO correlates well with hemodynamic indices of MV opening and closure, this noninvasive technique can be used as a reference in the timing of intracardiac events and in the determination of systolic and diastolic time intervals.

The echocardiographic determination of mitral valve opening and closure. Correlation with hemodynamic studies in man.

The ability of the echocardiogram to define mitral valve opening and closure was assessed by simultaneously recording the echocardiogram of the anterior leaflet (ECHO) with intracardiac pressures, aortic second sound, and ECG on 38 occasions in 14 patients undergoing cardiac catheterization. Hemodynamic opening and closure were defined by intersection of the pulmonary wedge and left ventricular pressures and the onset of left ventricular systole. The onset of the most rapid anterior motion (D') in early diastole and termination of the last rapid posterior movement in end diastole (Co) were used as echocardiographic markers of mitral valve opening and closure. Intervals measured included: the isovolumic relaxation period (IRP) from A2 to either hemodynamic (IRPH) or echocardiographic (IRPE) opening; the Q to closure interval (QCI) from the Q wave to either hemodynamic (QCIH) or echocardiographic (QCIE) closure; and diastolic filling period (DFP), either hemodynamic (DFPH) or echocardiographic (DFPE). The following significant (P less than .01) regression equations resulted: IRPE equals (.97) IRPH plus 30 (sem plus or minus 8 msec) r equals .89; QCIE equals (.68) QCIH plus 37 (sem plus or minus 7 msec) r equals .71; DEPE equals (.98) DFPH plus 10 (sem plus or minus 18 msec) r equals .98. Thus hemodynamic markers of opening and closure systematically precede echocardiographic markers of opening (D') and closure (Co) and the diastolic filling periods are equal within 10 msec. It is concluded that the echocardiogram of the anterior leaflet is a reliable indicator of hemodynamic markers of opening and closure of the mitral valve in man and is useful in the noninvasive determination of certain systolic and diastolic time intervals.