Carotid Pulse Recording Research Articles

Cardiac dysfunction in patients with chronic progressive external ophthalmoplegia

Chronic progressive external ophthalmoplegia (CPEO), which includes Kearns-Sayre syndrome, is a mitochondrial disorder with large deletions of mitochondrial DNA. Recently, mtDNA deletions in cardiac muscle cells were thought to be a cause of dilated cardiomyopathy. However, the cardiac involvement in patients with CPEO is generally considered to be limited to the cardiac conduction system. The purpose of this study was to evaluate left ventricular function in patients with CPEO. We evaluated the cardiac function of five patients with CPEO by means of carotid pulse recording and Doppler echocardiography. The ratio of the pre-ejection period to ejection time was increased to 0.67 in one patient and to 0.50 in another. Echocardiography showed left ventricular dilatation and diffuse hypokinetic wall motion in both cases. Left ventricular fractional shortening was decreased to 5 and 19%, respectively, and the mean rate of circumferential shortening was decreased to 0.12 and 0.63 circ/s, respectively. One of the two patient died of congestive heart failure 2 months after the study. The Doppler pattern of left ventricular filling in the three remaining patients showed a decrease in the ratio of peak flow velocity in early diastole to that in late diastole, with an increase in deceleration time. Although cardiac involvement in patients with CPEO is generally considered to be limited to the cardiac conduction system, left ventricular dysfunction may be present and should receive more attention in the management of patients with CPEO.

Serial effects on left ventricular load and contractility during hemodialysis in patients with concentric hypertrophy

To separate the effects of hemodialysis on loading conditions from those on contractile state, six patients with concentric left ventricular hypertrophy and normal left ventricular function were studied before, during, and after hemodialysis. Two-dimensional-directed M-mode ultrasound was used to measure left ventricular dimensions and wall thickness; a sphygmomanometer and carotid pulse recording were used to determine peak and end-systolic blood pressure. From these data, meridional stress at end systole was calculated and stress-dimension and stress-shortening relations were derived; measurements of metabolic parameters were made simultaneously. Heart rate and systolic blood pressure were stable throughout dialysis. Reductions in left ventricular dimensions and increased shortening were evident by 30 minutes of dialysis and were largely complete by mid-dialysis. These changes coincided with a decrease in potassium and an increase in ionized calcium but not in pH, which changed only in the latter half of dialysis. When stress-dimension and stress-shortening relations were examined, both individual and group data for all coordinates before, during, and after dialysis demonstrated an excellent linear fit consistent with a single contractile state. We conclude that in stable patients with left ventricular hypertrophy, the reduction in heart size and improvement in shortening are due primarily to reductions in preload and afterload.

Sensitivity of end-systolic pressure-dimension and pressure-volume relations to the inotropic state in humans.

The value for the slope of the left ventricular (LV) end-systolic pressure-dimension and pressure-volume relations has been proposed as a quantitative measure of the LV inotropic state. This measure of LV inotropic state is attractive because it is independent of preload and incorporates afterload. To investigate the sensitivity of the slope of these relations to alterations in contractile state, 10 normal subjects were studied using M-mode echocardiographic, phonocardiographic and indirect carotid pulse recordings during infusion of methoxamine to alter end-systolic pressure and during infusion of dobutamine (5 micrograms/kg/min) to increase LV inotropic state. Heart rate was maintained within a narrow range for each subject. End-systolic volume was calculated from end-systolic echocardiographic dimension by standard methods. End-systolic pressure was estimated from the dicrotic notch pressure determined from a calibrated carotid pulse recording; peak systolic pressure was also measured. Regardless of the method of approximating end-systolic pressure, the positive inotropic intervention caused a leftward shift in the end-systolic pressure-dimension and pressure-volume lines. With the dobutamine infusion, the value for the slope of the end-systolic pressure-dimension relation increased by 25% (range 16-46%, p less than 0.001), while the slope of the end-systolic pressure-volume relation increased by 55% (range 37-85%, p less than 0.001). In all cases, the curves were linear and became steeper with the positive inotropic intervention. In contrast, the value of the slope of the peak systolic pressure-end-systolic dimension relation showed a variable response to the dobutamine infusion (mean change 13%, range -77% to 73%; NS). Although the position of the peak systolic pressure-end-systolic dimension curve is consistently shifted with an alteration in inotropic state, the values of the slope of these curves are not reliable indicators of change in LV contractility. The values for the slope of the line relating end-systolic pressure (estimated by dicrotic notch pressure) to end-systolic dimension or volume, however, are highly sensitive to a change in inotropic state in human subjects.

Diagnosis of aortic stenosis in older age groups using external carotid pulse recording and phonocardiography.

Measurements made from carotid pulse tracings and phonocardiograms are helpful in the prediction of severe aortic stenosis in young patients. In the elderly, however, analysis of the carotid pulse tracing and, in particular, its maximum rate of rise has proved unreliable because the range of normal values for this age group has not been established. Consequently, we studied 44 young normal and 44 older normal subjects, 15 older patients with systolic hypertension, and 36 older patients with significant aortic stenosis. Measurements obtained from the carotid pulse included the left ventricular ejection time, upstroke time, half-rise time, and the maximum rate of rise. The peak of the systolic murmur in aortic stenosis was measured phonocardiographically from the Q wave of the simultaneously recorded electrocardiogram (QP interval). The results confirm that the maximum rate of rise of the carotid pulse of normal older subjects is much more rapid than that of young subjects. Among elderly patients with aortic stenosis, the maximum rate of rise falls within the range of the normal young. Measurement of the half-rise time is imprecise, and there is considerable overlap with the normal. This is also true of left ventricular ejection time. The upstroke time is unreliable because of wave distortion produced by the arteriosclerotic vascular bed. The two most valuable and easily recorded measurements are the maximum rate of rise and the QP interval. A maximum rate of rise of more than 1000 mmHg/s and a QP interval of less than 220 ms argue strongly against the diagnosis of severe aortic stenosis. These measurements provide a simple, non-invasive means of avoiding left heart catheterisation in older subjects suspected of having severe aortic stenosis.

Acute and chronic cardiocirculatory effects of oral prazosin in chronic refractory heart failure.

The acute hemodynamic effects of oral prazosin were investigated in 7 patients with chronic refractory heart failure. A single dose of 1 to 3 mg prazosin produced a significant increase in cardiac index (+17.6%, p less than 0.01) associated with substantial decreases in pulmonary arterial diastolic pressure (-31.6%, p less than 0.02), systemic vascular resistance (-29.7%, p less than 0.01), and double product (-24.1%, p less than 0.02). Plasma renin activity was significantly elevated (+42.4%, p less than 0.02). These effects were found maximum at 2 hours and persisted for 8 hours. The chronic hemodynamic effects in 5 patients with chronic refractory heart failure were evaluated by administration of 1 to 2 mg prazosin 3 times daily for 8 weeks, and ventricular function was assessed by echocardiography and carotid pulse recording. All the patients showed improvement in the clinical symptoms of heart failure. Peripheral venous pressure decreased slightly (-12.5%). ET/PEP increased (+24.5%) without any significant changes in EF and mVcf. Plasma renin activity also slightly increased (+17.8%). Thus, prazosin possesses sustained nitroprusside-like actions, and is effective in the management of chronic congestive heart failure refractory to conventional therapy. While, further investigation is necessary to define the effect of prazosin on plasma renin activity.

Assessment of the severity of aortic stenosis from the carotid pulse tracing.

The morphology of the externally recorded carotid pulse tracing was studied in 33 patients with valvular aortic stenosis for indices of severity. Comparisons were made with 10 normal controls. In aortic stenosis, initial upstroke time (IUT) of the carotid pulse, and left ventricular ejection time index were significantly higher and the rate of rise of the carotid pulse was slower than in the control group. Severity of stenosis (calculated valve area and mean pressure gradient) could not be predicted, however, from any of these indices. The IUT of the carotid pulse did correlate well with mean velocity of circumferential fiber shortening (mVcf) (r=-0.72). The rate of rise of the carotid pulse had also a correlation with mVcf(r=0.66). However, other commonly used hemodynamic indices (cardiac index, systemic vascular resistance, stroke volume, and ejection fraction) did not have a good correlation with IUT and rate of rise of the carotid pulse. These results suggest that we are able to separate by carotid pulse tracings aortic stenosis from normal subjects, but we cannot say what is the degree of severity of aortic stenosis from analysis of the external carotid pulse recording.

Severity of aortic stenosis assessed by carotid pulse recordings and phonocardiography.

The external carotid pulse, the PCG, and the ECG were studied in 26 adult patients with valvular aortic stenosis whose systolic peak pressure gradients ranged from 18 to 165 mmHg. A significant correlation was found between the rapidity of the pulse upstroke, as measured by the T-time, and the location of the peak of the systolic murmur during ventricular ejection, on the one hand, and the gradient, on the other. The left ventricular ejection time (LVET) related directly and the pre-ejection period (PEP) indirectly with the gradient. There was a signficant inverse relationship between the PEP/LVET quotient and the pressure gradient but this quotient did not classify the patients according to the severity of the stenosis as well as the T-time and the location of the peak of murmur. When a combination of the T-time, the PEP/LVET, and the location of the peak of the murmur was used in each patient, a good discrimination between the patients was achieved. When the pressure gradient was above 50 mmHg, at lease one of the measurements was abnormal and when it exceeded 100 mmHg, at least two measurements were abnormal. The study further showed that it is possible to separate patients with valvular aortic stenosis from those with hypertrophic obstructive cardiomyopathy lidiopathic hypertrophic subaortic stenosis) or mitral insufficiency on the basis of carotid pulse tracings and PCGs.

Short-Term Effects of Smoked Marihuana on Left Ventricular Function in Man

The short-term effects of smoking one to three marihuana cigarettes (900 mg of marihuana per cigarette; 2.2% delta9-tetrahydrocannabinol) on left ventricular performance were evaluated in 21 experienced users of cannabis at different times during a 94-day in-hospital study of the biologic effect of daily heavy smoking of marihuana. In six subjects, cardiac output was determined using the indocyanine-green dye-dilution technique; and in two of these individuals and 15 additional subjects, cardiac output, ejection fraction, preejection period (PEP), left ventricular ejection time (LVET), and the velocity of circumferential fiber shortening (Vcf) were determined using echocardiograms, phonocardiograms, and carotid pulse recordings. Following the smoking of one to three marihuana cigarettes, the heart rate rose 16 to 53 percent, cardiac output rose 4 to 9 percent, stroke volume did not change or fell slightly, and ejection fraction, PEP/LVET, and did not change, except for a slight increase in Vcf (15%) after three marihuana cigarettes, which could be accounted for by the associated increase in heart rate (53%). These findings suggest that in long-term heavy users of cannabis, marihuana has no significant effect on myocardial contractility independent of its effect on heart rate.

External carotid pulse recordings in hypertrophic obstructive cardiomyopathy.

External carotid pulse tracings were examined in 15 patients with hypertrophic obstructive cardiomyopathy (HOCM), the diagnosis being confirmed by catheterization of the left heart. Of 12 patients with intraventricular gradients at rest, 9 had a typical bifid pulse with midsystolic dipping. In one patient without a gradient at rest, midsystolic dipping occurred only in beats following extrasystoles (Brockenbrough phenomenon). The upstroke of the pulse wave was rapid in all the patients, a finding that distinguishes them from patients with valvular aortic stenosis. There was a correlation between the length of the left ventricular ejection time and the intraventricular gradient (r = 0.71) but as more than half the patients had normal or shortened ejection times, the diagnosis of HOCM cannot be based on measurements of this parameter. It is concluded that carotid pulse registrations are of considerable diagnostic value in patients suspected of having HOCM. As the pulse changes are correlated to the degree of left ventricular outflow obstruction, it is suggested that repeated pulse tracings may be used as a means for controlling the degree of obstruction once the diagnosis has been established in the individual patient.

Alterations in preload and ejection phase indices of left ventricular performance,.

Ejection phase indices such as mean velocity of circumferential fiber shortening (V-cf), ejection fraction (EF), and mean normalized systolic ejection rate (MSER) are thought to reflect the level of left ventricular (LV) inotropic state. Although known to be influenced by changes in afterload, their response to altered preload is less certain. This question was examined in ten normal subjects studied in the supine position and after 10 min of 75 degree head-up tilt. Echo VL diameter (D) and carotid pulse recordings were used to calculate LV ejection time, V-cf, MSER, LV end-diastolic and stroke volumes (EDV and SV, by D3 formula), and ejection fraction. Systemic blood pressure (BP)was measured by cuff, and heart rate (HR) counted from the ECG. Calculated LVEDV decreased with tilt (115 plus or minus 8 to 82 plus or minus 7 ml, P smaller than 0.001), as did SV (81 plus or minus 6 to 54 plus or minus 6 ml, P smaller than 0.001), and ejection time (0.31 plus or minus 0.01 to 0.27 plus or minus 0.00 sec, P smaller than 0.001), but there was no significant change in systolic or diastolic BP or HR. V-cf, EF, and MSER were not singificantly altered by tilt (1.09 plus or minsu 0.04 to 1.12 plus or minus 0.05 circ/sec; 0.70 plus or minus 0.02 to 0.65 plus or minus 0.02; and 2.29 plus or minus 0.07 to 2.43 plus or minus 0.08 end-diastolic volumes/sec, respectively). V-cf, MSER, and EF appearrelatively unaffected by acute alterations in preload. That compensatory sympathetic responses blunted potential changes cannot be excluded, although HR was not found to have increased.

Systolic Time Intervals

The diagnosis of tight aortic stenosis is always an important consideration in patients with congestive heart failure of unknown origin. Inasmuch as the typical systolic murmur of aortic stenosis may be soft and difficult to hear under such circumstances, this diagnosis may be missed or, at best, difficult to confirm. We examined phonocardiograms with carotid pulse recordings and measured systolic time intervals in patients with aortic stenosis and congestive heart failure to determine if systolic time intervals were of any help. Left ventricular ejection time (LVET) was prolonged in seven of nine patients. The pre-ejection period (PEP)/LVET ratio in all nine cases was found to be much lower than values reported for congestive heart failure from other causes. It is believed that the PEP/LVET ratio is very helpful in distinguishing congestive heart failure due to aortic stenosis from congestive heart failure caused by other diseases and may be very helpful

Systolic time intervals. Use in congestive heart failure due to aortic stenosis.

The diagnosis of tight aortic stenosis is always an important consideration in patients with congestive heart failure of unknown origin. Inasmuch as the typical systolic murmur of aortic stenosis may be soft and difficult to hear under such circumstances, this diagnosis may be missed or, at best, difficult to confirm. We examined phonocardiograms with carotid pulse recordings and measured systolic time intervals in patients with aortic stenosis and congestive heart failure to determine if systolic time intervals were of any help. Left ventricular ejection time (LVET) was prolonged in seven of nine patients. The pre-ejection period (PEP)/LVET ratio in all nine cases was found to be much lower than values reported for congestive heart failure from other causes. It is believed that the PEP/LVET ratio is very helpful in distinguishing congestive heart failure due to aortic stenosis from congestive heart failure caused by other diseases and may be very helpful

Assessing the severity of aortic stenosis by phonocardiography and external carotid pulse recordings.

Phonocardiograms and carotid pulse tracings were done on a group of 47 patients with all degrees of aortic stenosis and were compared with two groups of normals. Indices evaluated were pre-ejection period, left ventricular ejection time, maximum rate of arterial pulse rise, arterial half rise time (T time) and upstroke time, and timing of the peak intensity of the systolic murmur in relation to the electrocardiographic QRS and first heart sound. The indices most indicative of the presence of aortic stenosis and best correlated with its severity were the ejection time index, the maximal rate of rise of the carotid pulse and the timing of the peak of the systolic murmur. If, in a given case, all three of these indices fall outside of certain limits (ejection time index >0.42 sec, maximum rate of arterial pulse rise <500 mm Hg/sec, and Q wave to peak of murmur >0.19 sec), then severe aortic stenosis is almost invariably present.

Physical signs in differential diagnosis of left ventricular obstructive cardiomyopathy.

The diagnosis ofleftventricular obstructive cardiomyopathy can bemadeinmostinstances by simple clinical examination, as practised byPaul Wood asearly as 1960(personal communication). Occasionally, thereisdifficulty indifferentiating other causesofa systolic murmur associated with leftventricular disease. We have,therefore, assessed thediagnostic valueofpalpation ofthe carotid pulse andindirect carotid pulse recording, palpation ofthepraecordium anddisplacement recording, andauscultation andphonocardiography, inleft ventricular obstructive cardiomyopathy with and without additional mitralregurgitation, in aortic valve andfixed subvalve stenosis, andinpure mitral regurgitation.

Significance of systolic murmurs in the aged.

Abstract A prospective study of the heart murmurs in 30 elderly patients, none of whom had a history of rheumatic heart disease, was undertaken by use of phonocardiography, carotid-pulse recording and amyl nitrite. Systolic ejection murmurs were recorded in 29 patients, 24 increasing in intensity with amyl nitrite inhalation. Twelve had abnormal carotid-pulse tracings typical of aortic stenosis. There were few of the usual associated clinical findings of aortic stenosis. Other findings such as atrial gallops and diastolic murmurs were not infrequent. It appears that the degenerative changes seen at the aortic valve in the aged not only cause enough turbulence for a murmur to occur but may frequently obstruct the aortic valve.

Aortic stenosis: A study with particular reference to an indirect carotid pulse recording in diagnosis

The clinical findings in 70 individuals with aortic stenosis are reported. Confirmation of the diagnosis was available in 28. Special emphasis was placed on the indirect recording of the carotid pulse as a diagnostic aid. By means of a “tuned” system, the characteristic contour of aortic stenosis, consisting of a plateaued curve with systolic vibrations, was obtained in 68 of the 70 patients (97 per cent). It is felt that the method described offers a simple and practical diagnostic aid.

Advance in the clinical evaluation of aortic stenosis by arterial pulse recordings of the neck

The principle of arterial oscillometry has been applied to the cervical vessels by connecting a cuff placed around the neck to a recording differential manometer. This instrument is essentially pneumatic without recourse to electronics. It has previously been described by the authors. The tracings obtained at a level of counterpressure of 10 to 20 mm. Hg, which is easily tolerated, display features almost identical to the carotid sphygmograms. This indirect process of carotid pulse recording has been applied to twenty-eight cases of aortic stenosis. The characteristics of the curves in aortic stenosis principally consist in a slowing of the upstroke with superimposed vibrations, a delayed single summit, and a straightening of the descending limb. The time spent for reaching the half-way point on the ascent has proved a ready quantitative appreciation of the slanted upstroke. It appears to correspond to the degree of stenosis. Associated valvular disease like aortic insufficiency or mitral stenosis does not modify this criterion. The value of the method in differential diagnosis is stressed.