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PubMed1978

Echocardiographic left ventricular function in mitral stenosis.

Left ventricular function was measured by echocardiography in 22 patients with pure mitral stenosis. Thirteen patients underwent closed transventricular mitral valvulotomy and nine underwent open mitral valvulotomy using cardiopulmonary bypass. Preoperative left ventricular function was normal in most patients but was depressed in older subjects (P less than 0.05) and in those undergoing a second operation on the mitral valve (P less than 0.001). The decrease in left ventricular function was probably related to the duration of mitral valve disease, with fibrosis and rigidity of the subvalvar apparatus and posterobasal left ventricular wall. There was no change in ventricular dimensions or in left ventricular function as measured by percentage shortening of the left ventricular diameter and ejection fraction 7 to 12 days after open or closed mitral valvulotomy.

Adult↗
PubMed1977

Determinants of left ventricular function following aorto-coronary bypass surgery.

Ventricular function was evaluated by the development of ventricular function curves from the vulumes stress of angiographic contrast media in 30 patients before and an average of 5 months after coronary bypass surgery. Patients were grouped according to preoperative operative indications, perioperative events, and postoperative status to determine the most important factors affecting postoperative ventricular function. Progression of lesions in the native coronary circulation correlated most significantly with a decrease in postoperative ventricular function. In 18 of 19 patients the changes in native coronary circulation were progression to complete occlusion. Seventy-three per cent of these changes were associated with a patent graft distal to the change. Patients with very ischemic ventricles as evidenced by a markedly positive stress test (greater than 2 mm. ST depression) and/or main left coronary obstruction maintained or improved postoperatively ventricular function. Increase in postoperative ejection fraction was often associated with decrease in aortic mean pressure, making it difficult to use this parameter to evaluate postoperative ventricular function.

Aorta↗
PubMed2002

Tissue Doppler imaging assessment of long axis left ventricular function in hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy is classically defined as a diastolic disease with normal systolic function. Long axis left ventricular function is an important and sensitive determinant of global ventricular function but its assessment is often difficult and complex. Tissue Doppler imaging of the mitral annulus allows the study of long axis left ventricular function. METHODS: 47 patients with non-obstructive hypertrophic cardiomyopathy and 45 healthy volunteers, matched by age and sex, were studied with pulsed tissue Doppler imaging of the 4 sides of the mitral annulus (septal, lateral, inferior, anterior) in 4 and 2 chamber views. In each wave (systolic-s, rapid filling-e, atrial contraction-a) we analyzed velocities, time intervals and velocity-time integrals, as well as heterogeneity and asynchrony. Data were compared among the different sides in each group, between groups and with conventional Doppler data. RESULTS: In contrast to normal subjects, hypertrophic cardiomyopathy patients showed: 1--Systolic function: lower velocities, longer systolic time intervals (isovolumic relaxation time, time to peak s, ejection time), higher systolic asynchrony (time to peak s, ejection time, systolic time) and lower s/shortening fraction ratio. These changes occurred despite normal indices of global systolic function. 2--Diastolic function: lower velocities (much lower rapid filling velocity, lower atrial contraction velocity, lower septal e/a), higher e/a heterogeneity index, longer protodiastolic times (isovolumic relaxation time and time to peak e), higher diastolic asynchrony (time to peak e) and lower e wave integral. Hypertrophic cardiomyopathy patients also showed higher average number of annular sides with e/a < 1 per patient and higher percentage of e/a < 1, mainly on the septal side. CONCLUSIONS: This study shows that: 1--Tissue Doppler imaging allows the detailed analysis of long axis left ventricular function in hypertrophic cardiomyopathy patients. 2--Long axis systolic function is abnormal in this disease, even in the presence of normal indices of global systolic function. 3--Long axis diastolic function is deeply disturbed in hypertrophic cardiomyopathy, at ventricular and atrial levels. 4--Long axis dysfunction occurs in annular sides contiguous to hypertrophied and non-hypertrophied walls, highlighting the role of other factors in its pathophysiology.

Adolescent↗
PubMed2005

Adenylyl cyclase type V deletion increases basal left ventricular function and reduces left ventricular contractile responsiveness to beta-adrenergic stimulation.

We tested the hypothesis that deletion of adenylyl cyclase type V (AC(V)) would be associated with decreased left ventricular (LV) contractile function and responsiveness to beta-adrenergic receptor (betaAR) stimulation. Absence of cardiac AC(V) expression was confirmed by RT-PCR and immunoblotting in AC(V)-deleted mice (AC(V) (-/-)). Compared to sibling mice with normal amounts of AC(V) (CON), basal and water-soluble forskolin derivative NKH477-stimulated cAMP production was reduced in both LV homogenates and in isolated cardiac myocytes. Basal LV +dP/dt (isolated perfused hearts) was increased (CON: 3,649 +/- 247 mmHg/s; AC(V) (-/-): 4,625 +/- 350 mmHg/s; p = 0.035, n = 10), but the potency of dobutamine on LV +dP/dt was decreased by AC(V) deletion (log EC(50): CON: -6.83 +/- 0.14 M; AC(V) (-/-): -5.99 +/- 0.15 M; p = 0.0007, n = 10). The initial rates of ATP-dependent sarcoplasmic reticulum calcium uptake, assessed in LV homogenates, showed that AC(V) deletion increased SERCA2a affinity for Ca(2+) (log EC(50): CON: -5.94 +/- 0.03 M; AC(V) (-/-): -6.09 +/- 0.02 M; p = 0.001, n = 8). AC(V) deletion is also associated with increased phospholamban phosphorylation, decreased type 1 protein phosphatase catalytic subunit content and activity, and reduced cardiac Galphas protein content. In conclusion, AC(V) deletion has a favorable effect on basal LV function despite reduced cAMP levels. Increased SERCA2a affinity for Ca(2+) and increased phospholamban phosphorylation are contributing factors. However, AC(V) deletion is associated with reduced LV contractile responsiveness to betaAR stimulation, an effect that is associated with reduced Galphas protein content and reduced cAMP generating capacity in cardiac myocytes.

Adenylyl Cyclases↗
PubMed1990

[The effects of lorcainide on the ECG pattern and left ventricular function in a patient with recurrent ventricular tachycardia].

The paper presents an adverse effect of Lorcainide on the electrocardiographic pattern and left ventricular function in a patient with recurrent ventricular tachycardia in the course of arterial hypertension and ischemic heart disease. Based upon this case report a relatively new and not well known phenomenon of drug arrhythmogenesis is presented.

Anti-Arrhythmia Agents↗
PubMed1980

Noninvasive assessment of the effects of aorta-coronary bypass grafting on ventricular function during rest and exercise.

Ventricular function was measured by radionuclide angiocardiography during rest and exercise in patients before and approximately 4 months after aorta-coronary bypass grafting. The first group of seven patients continued to have symptomatic chest pain after operation. The second group of 13 patients were asymptomatic after operation but, since they had been studied before operation, consented to postoperative study. Before operation, both patient groups demonstrated similar degrees of myocardial ischemia during exercise as documented by a decrease in ejection fraction, by large increases in end-diastolic and end-systolic volumes, and by exercise-induced wall motion abnormalities. After aorta-coronary bypass grafting, ventricular function in the symptomatic patients was unchanged during rest and exercise. In contrast, ventricular function during rest and exercise in the asymptomatic patients was markedly improved. With exercise, the ejection fraction increased and the exercise-induced wall motion abnormalities seen before operation were abolished. Therefore, aorta-coronary bypass grafting can effectively reverse exercise-induced left ventricular dysfunction in patients with coronary disease. Moreover, the change in left ventricular function demonstrated by radionuclide angiocardiography correlated with the clinical status of the patient groups.

Cardiac Output↗
PubMedDate not supplied

Doppler echocardiographic index for assessment of global right ventricular function.

Echocardiographic assessment of right ventricular function remains difficult and challenging. However, there is considerable clinical need for a simple, reproducible, and reliable parameter of right ventricular function in patients with right-sided heart disease. The purpose of this study was to assess the clinical value of a Doppler-derived index, combining systolic and diastolic intervals of the right cycle, in assessing global right ventricular function in patients with primary pulmonary hypertension. The study population comprised 26 consecutive patients with primary pulmonary hypertension and 37 age-matched normal subjects. The sum of right ventricular isovolumetric contraction time and isovolumetric relaxation time was obtained by subtracting right ventricular ejection time from the interval between cessation and onset of the tricuspid inflow velocities with pulsed-wave Doppler echocardiography. An index of combined right ventricular systolic and diastolic function was obtained by dividing the sum of both isovolumetric intervals by ejection time. The index was compared with available parameters of systolic or diastolic function, clinical symptoms, and survival. Right ventricular isovolumetric contraction time and isovolumetric relaxation time were prolonged significantly in patients with primary pulmonary hypertension (85 +/- 41 msec and 135 +/- 43 msec) compared with normal subjects (38 +/- 7 msec and 49 +/- 9 msec, respectively; p < 0.001). Ejection time was shortened significantly in patients with pulmonary hypertension (241 +/- 43 msec versus normal [322 +/- 21 msec]; p < 0.001). However, the index was the single most powerful variable to discriminate patients with primary pulmonary hypertension from normal subjects (0.93 +/- 0.34 versus 0.28 +/- 0.04; p < 0.001) and was the strongest predictor of clinical status and survival. The index was not significantly affected by heart rate, right ventricular pressure, right ventricular dilation, or tricuspid regurgitation. It is well known that right ventricular systolic and diastolic dysfunction coexist in patients with primary pulmonary hypertension. This article reports the use of an easily obtainable Doppler-derived index that combines elements of systolic and diastolic function. This index appears to be a useful noninvasive means that correlates with symptoms and survival in patients with primary pulmonary hypertension.

Adult↗
PubMed2006

Effects of on-pump versus off-pump coronary artery bypass graft surgery on right ventricular function.

OBJECTIVES: Right ventricular dysfunction is a possible cause of cardiac failure after coronary surgery. The use of cardiopulmonary bypass is regarded as a major cause for its occurrence, and it has been postulated that performing coronary surgery without cardiopulmonary bypass might reduce ventricular dysfunction. Therefore, this prospective, randomized, controlled study tested the hypothesis that off-pump coronary surgery would better preserve right ventricular systolic and diastolic function than conventional bypass surgery. METHODS: Fifty patients scheduled for elective coronary artery bypass surgery were randomly assigned to conventional or off-pump surgery. Right ventricular function was assessed by intraoperative transesophageal echocardiography immediately before and after coronary surgery. Right ventricular ejection fraction was used as a marker of global systolic function and tricuspid early/late (atrial) ratio as a marker of the global diastolic function. Peak systolic and early diastolic velocities of the lateral tricuspid annulus were studied to assess systolic and diastolic function in the area of the right ventricular free wall. RESULTS: Surgery was completed according to randomization in 48 of 50 patients. Preoperative characteristics were similar in both groups. Intraoperative differences between the two groups included a higher volume of allogeneic blood transfusion in the conventional surgery group. At the end of surgery, global systolic right ventricular function was similarly maintained and diastolic function similarly impaired in both groups. There were no significant intergroup differences in any of the echocardiographic markers of right ventricular function. CONCLUSIONS: Off-pump surgery did not better preserve right ventricular systolic and diastolic function than did conventional coronary surgery.

Aged↗
PubMed2002

Deterioration of left ventricular function following atrio-ventricular node ablation and right ventricular apical pacing in patients with permanent atrial fibrillation.

AIMS: Transcatheter radiofrequency ablation of the atrio-ventricular (AV) node followed by ventricular pacing has been shown to improve symptoms and quality of life of patients with atrial fibrillation (AF). It is assumed that function improves, but this has been less well demonstrated. The aim of this study was to assess the long-term effect of AV node ablation and ventricular pacing on left ventricular ejection fraction (LVEF) in patients with permanent AF. METHODS AND RESULTS: All 12 patients studied had permanent AF for at least 12 months (mean age 70 years, range 41 to 78). LVEF was determined 6 days and 3 months after AV node ablation by radionuclide ventriculography, at a paced rate of 80 beats . min (-1). Cardiac dimensions were measured by means of transthoracic echocardiography. No major changes in pharmacological therapy were made during 3 months follow-up period. LVEF showed a significant deterioration after 3 months follow-up period for the group (47.5 +/- 14.4%; 6 days after ablation vs 43.2 +/- 13.7%; 3 months after ablation, P < 0.05). There were no significant differences in left ventricular cavity dimensions directly after AV node ablation and 3 months later (LVEDD 51.2 +/- 10.7 mm vs 52.6 +/- 8.6 mm, P = NS: LVESD: 36.1 +/- 14.2 mm vs 36.6 +/- 9.7 mm, P = NS). Left atrial size did not show reduction 3 months after AV node ablation (50.8 +/- 13.6 mm vs 51.0 +/- 14.1 mm, P = NS). CONCLUSION: The restoration of a regular ventricular rhythm following AV node ablation for patients in permanent AF does not result in improvement in left ventricular function.

Adult↗
PubMed1979

Failure of aneurysmectomy to improve left ventricular function.

Biplane left ventricular angiography was performed in 22 patients with isolated obstructive disease of the anterior descending branch of the left coronary artery and with an anterior aneurysm following transmural myocardial infarction. Six patients were restudied between 6 and 10 months after aneurysmectomy. Left ventricular reserve was estimated by analysis of a spontaneous postextrasystolic beat. Using angiographic techniques a contractile section, a transitional section, and a noncontractile section were identified. From the surgical patients the excised aneurysm and a transmural needle biopsy of the transitional section were investigated by light microscopy. With increasing volumes of noncontractile and transitional sections, total end-diastolic volume (r = 0.81, P less than 0.001) and end-systolic volume (r = 0.94, P less than 0.001) increased linearly, while the ejection fraction decreased (r = 0.70, P less than 0.001). No relation was found between the combined volumes of the noncontractile and transitional sections on the one hand, and the end-diastolic volume, the end-systolic volume, or the ejection fraction of the contractile section on the other hand. After aneurysmectomy a significant decrease was found in end-diastolic volume (194 to 133 ml/m2, P less than 0.001) and end-systolic volume (124 to 83 ml/m2, P less than 0.001) but no change occurred in ejection fraction (35 to 37%) and left ventricular end-diastolic pressure (23 to 25 mmHg). Surgical resection included part of the transitional section, which before surgery had an average ejection fraction of 27 per cent during a normal beat, rising to 41 per cent in a postextrasystolic beat. The transitional section after surgery now formed a large akinetic area of the anterior wall. We conclude that aneurysmectomy in isolated left anterior descending artery disease with anterior aneurysm fails to improve left ventricular function because the effect of reduction of left ventricular volumes is offset by the destruction of contractile behaviour in the transitional section.

Adult↗
PubMed2004

[Influence of congenital hypothyroidism on left ventricular function of neonates].

OBJECTIVE: To evaluate left ventricular function in neonates with congenital hypothyroidism (CH) and its correlation with thyroid hormones serum levels. METHODS: M-mode echocardiography [left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS)], pulse wave Doppler [the peak early diastolic mitral inflow velocity (Em), the peak late diastolic mitral inflow velocity (Am)], quantitative tissue velocity imaging (QTVI) [the systolic peak mitral annular velocity (sm), the early diastolic peak mitral annular velocity (em), the late diastolic peak mitral annular velocity (am)] and tissue tracking imaging (TTI) [the systolic mitral annular displacement (MAD)] were evaluated in 35 neonates with congenital hypothyroidism aged 15-28 days and 30 normal neonates in this study. Correlation analysis was also made between left ventricular function and serum TT3, TT4 and TSH levels. RESULTS: Left systolic function parameters (LVEF, LVFS, sm and MAD) were 0.62 +/- 0.08, (28.21 +/- 5.31)%, (2.58 +/- 0.59) cm/s and (0.27 +/- 0.07) cm, respectively, in CH group, and 0.67 +/- 0.06, (31.16 +/- 4.13)%, (3.24 +/- 0.52) cm/s and (0.41 +/- 0.08) cm in control group (P < 0.05, P < 0.01). Left diastolic function parameters (Am, Em/Am, em/am, Em and em) were (0.59 +/- 0.10) m/s, 0.98 +/- 0.18, 0.82 +/- 0.40, (0.57 +/- 0.11) m/s and (2.83 +/- 1.48) cm/s, respectively, in CH group, and (0.65 +/- 0.10) m/s, 1.14 +/- 0.20, 1.25 +/- 0.33, (0.73 +/- 0.11) m/s and (4.46 +/- 1.29) cm/s in control group (P < 0.05, P < 0.01). MAD, sm, Em and em in CH group were greatly lower than that in control group (P < 0.001). Left systolic function (LVEF, sm, MAD) and diastolic function (Em, Am, em, em/am) were positively correlated with TT3, TT4 serum levels (P < 0.05, P < 0.01), and negatively with TT4 serum levels (P < 0.05, P < 0.01). MAD, Em and em were highly correlated with TT4, TSH serum levels (r = 0.700, r = 0.564, r = 0.593, r = 0.564, P < 0.001; r = -0.674, r = -0.521, r = -0.578, r = -0.632, P < 0.001). CONCLUSIONS: Neonates with CH have lower left systolic and diastolic function. Left ventricular function was affected by thyroid hormones. QTVI and TTI are more sensitive parameters in evaluating left ventricular function of neonates with congenital hypothyroidism than conventional echocardiography.

Congenital Hypothyroidism↗
PubMed2006

MDCT of right ventricular function: comparison of right ventricular ejection fraction estimation and equilibrium radionuclide ventriculography, part 1.

OBJECTIVE: The aim of this study was to calculate right ventricular ejection fraction by use of ECG-gated MDCT and to compare the results with those of equilibrium radionuclide ventriculography. SUBJECTS AND METHODS: Forty-nine consecutively examined patients (30 men, 19 women; mean age, 59 years) with known or suspected right ventricular dysfunction secondary to bronchopulmonary (n = 30) or pulmonary vascular (n = 19) disease underwent ECG-gated 16-MDCT angiography of the heart (rotation time, 0.42 second; 120 kV; 300 mAs; collimation, 12 x 0.75 mm; pitch, 0.2) after CT angiographic examination of the entire thorax according to a standard protocol. Biphasic administration of a 30% contrast agent was systematically performed (phase 1, 90 mL at 3 mL/s; phase 2, 30 mL at 1.5 mL/s); no patient received additional medication. Right ventricular ejection fraction was calculated after two reviewers in consensus determined the reconstruction windows and segmentation of the right ventricular cavity on a series of diastolic and systolic short-axis images. The results were compared with those of equilibrium radionuclide ventriculography. RESULTS: At data acquisition, the mean (+/- SD) heart rate of the study group was 82 +/- 13.87 beats per minute (BPM) (range, 51-115 BPM). ECG showed a sinus rhythm in 30 (61%) of the patients and irregular cardiac rhythm in 19 (39%) of the patients. Agreement between the two techniques was estimated by intraclass correlation coefficient (0.77), the method of Bland and Altman (limits of concordance, -14.9 and 13.7), and percentage of variability between two measurements expressed by mean absolute percentage error (12.1%). The estimated effective dose for heart examination was 7.48 mSv with CT and 5 mSv with scintigraphy. The mean effective dose for the chest and heart CT examinations was 11.64 mSv. CONCLUSION: Right ventricular ejection fraction can be reliably estimated with 16-MDCT in unselected patients.

Adult↗
PubMed1976

Left ventricular angiography on exercise. A new method of assessing left ventricular function in ischaemic heart disease.

Left ventricular function was studied in 17 patients with ischaemic heart disease and compared with 4 patients with normal left ventricular function. The patients in the homogeneous group of ischaemic heart disease were further subdivided into those 'without angina' (n=5) and those 'with angina' (n=12), depending upon the presence of angina during supine leg exercise at the time of definitive study. At rest there was no significant difference in the heart rate, cardiac output, stroke volume, and left ventricular end-diastolic pressure (LVEDP) in the three groups. During exercise the cardiac output and stroke volume were significantly depressed and LVEDP was significantly raised in the ischaemic heart disease group as a whole but within this group failed to show any significant difference in patients with and without angina. The left ventricular end-diastolic volume (LVEDV) and end-systolic volume (LVESV) measurements showed clear separation of these three groups only on exercise. On exercise, there was decrease in LVEDV and LVESV (P less than 0.05; P less than 0.02) in the group with normal left ventricular function, no change in the group with ischaemic heart disease without angina, and striking increase in LVEDV and LVESV in the group with ischaemic heart disease and angina (P less than 0.01 and P less than 0.02, respectively). This angiographic method of assessing left ventricular function shows clear separation of the three groups and also highlights the significance of angina. Ejection fraction (EF), a commonly measured parameter of left ventricular function, failed to reflect consistent changes on exercise as compared to values at rest which emphasizes the limitations of the measurement of ejection fraction at rest.

Adult↗
PubMed1983

Atrial transport function in coronary artery disease: relation to left ventricular function.

The atrial contribution to ventricular stroke volume was evaluated in 50 patients with coronary artery disease and found to be related to left ventricular function. All patients underwent complete hemodynamic and angiographic studies. Angiographic volume studies were utilized to determine atrial contribution to the stroke volume, end-systolic volume and ejection fraction. In 11 patients without heart disease, atrial contribution to stroke volume was (mean value +/- standard deviation) 9.3 +/- 6 ml/m2 compared with 13.5 +/- 6 ml/m2 in the patients with coronary disease (probability [p] less than 0.05). The percent of atrial contribution to stroke volume was 20 +/- 7 and 33 +/- 11%, respectively, in normal subjects and patients with coronary disease (p less than 0.05). The combination of congestive heart failure and cardiomegaly was the only clinical aspect associated with a significantly higher (p less than 0.05) atrial contribution to stroke volume than that in the remaining patients with coronary disease (46 versus 31%). Relating the atrial contribution to stroke volume to the left ventricular end-diastolic pressure, stroke volume, end-systolic volume and ejection fraction revealed correlation coefficients of 0.30, -0.44, 0.56 and -0.64, respectively. No patient with a normal ejection fraction (greater than 0.50) had an atrial contribution greater than 40% of stroke volume. The ratio of peak left ventricular systolic pressure/end-systolic volume (mm Hg/ml) was 2.7 +/- 1.5 in patients (n = 14) with an atrial contribution greater than 40% of stroke volume compared with 5.3 +/- 3.4 in patients having an atrial contribution of 40% or less (p less than 0.01). These findings indicate that atrial contribution to stroke volume is inversely related to left ventricular function.

Adult↗
PubMed1980

An equilibrium radionuclide technique to assess the effect of propranolol on left ventricular function in thyrotoxicosis.

Radionuclide imaging of the left ventricular blood pool provides a convenient non-invasive method of monitoring left ventricular function. Left ventricular function is characterised by the left ventricular curve which represents all phases of the cardiac cycle and is obtained by a multiple gated equilibrium method (MUGA). Volume curves were obtained over a minimum 1 1/2 h period in 15 normal subjects and in 20 thyrotoxic patients. Changes in left ventricular ejection fraction (LVEF), maximum ejection fraction rate and total electromechanical time interval were recorded from volume curve data. To assess the effect of pharmacological intervention, serial measurements of LVEF were made before and after 40 mg oral propranolol. In thyrotoxic patients, LVEF decreased by 17% of the initial value and in normal subjects by less than 10% following propranolol. This method can be extended to assess the effects of physiological or pharmacological intervention on left ventricular function in other disease states.

Adult↗
PubMed1989

[Silent myocardial ischemia evaluated by ambulatory left ventricular function monitoring].

To determine whether left ventricular function is less disturbed in asymptomatic ischemia than in symptomatic ischemia, exercise-induced left ventricular function was measured in beat-to-beat using an ambulatory left ventricular function monitoring system. The study subjects were 22 patients with coronary artery disease. Supine and sitting ergometer exercise tests were performed. Of 44 exercise tests, 33 showed significant ST depression on electrocardiograms. Among these 33, 17 were asymptomatic: 16, symptomatic. The left ventricular functions during exercise of these 33 were analyzed and compared with those of five normal controls. The changes in end-diastolic volume were not so significant either in controls or in the asymptomatic and symptomatic groups, but the changes in end-systolic volume were reversed in the diseased groups, particularly in the symptomatic group. The changes in ejection fraction (EF), therefore, were significantly negative in the diseased group, particularly in the symptomatic group. The correlation between exercise-induced left ventricular dysfunction and symptoms was evaluated among the 33 patients. Symptoms were present in 35% (6/17) in less than 10% decrease in EF, 44% (4/9) in 10-15% decrease, and 85% (6/7) in greater than or equal to 15% decrease, respectively. Thus, asymptomatic ischemia represents a lesser degree of myocardial ischemia as indicated by mild left ventricular dysfunction, compared with symptomatic ischemia. However, some cases of severe myocardial ischemia did not develop symptoms. We concluded that silent myocardial ischemia is responsible for a lesser degree of myocardial ischemia and decreased pain perception.

Electrocardiography, Ambulatory↗
PubMed1983

Effects of oral digoxin on ventricular ectopy and its relation to left ventricular function.

The ventricular antiarrhythmic properties of oral digoxin were examined in 13 patients with chronic ventricular ectopy using serial 24-hour electrocardiographic monitoring. Mean premature ventricular complex frequency (per 1,000 normal beats) decreased from 56 +/- 47 during the placebo period to 40 +/- 27 (p = not significant [NS]) and 25 +/- 17 (p less than 0.05) during daily administration of digoxin, 0.25 and 0.375 mg. Digoxin had no significant effect on the qualitative occurrence of complex ventricular arrhythmia patterns (multiformity, bigeminy, couplets, ventricular tachycardia). Radionuclide left ventricular (LV) ejection fraction was measured during the placebo period. Seven patients had normal (ejection fraction greater than 50%) and 6 abnormal global LV performance. In the normal group, the mean premature ventricular complex frequency decreased from 69 +/- 58 to 20 +/- 18 (p less than 0.05) and the mean couplet frequency decreased from 0.59 +/- 0.85 to 0.07 +/- 0.06 (p less than 0.04) during the placebo and 0.375 mg digoxin dosing periods, respectively. In contrast, no significant changes in either variable occurred after digoxin in subjects with depressed LV function. This study indicates that oral digoxin is moderately effective in suppressing premature ventricular complexes, and that its effects are greatest in patients with normal overall LV performance.

Administration, Oral↗