Noninvasive evaluation of the effect of timolol on left ventricular performance after myocardial infarction and the consequence for prognosis

Brubakk, Oddbjørn; Pedersen, Terje R.; Overskeid, Kåre

doi:10.1016/s0735-1097(87)80094-3

Cited by 8 publications

(5 citation statements)

References 21 publications

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“…The estimation of cardiac time intervals using PCG, SCG and ICG, investigated in this study, offers an opportunity to assess cardiac contractility which, in addition to the analysis of the other features of these signals, broadens the potential of SCG, PCG and ICG in the monitoring of cardiovascular performance. As these technologies yield themselves to wearable applications, they could be used outside of the hospital/clinical settings to detect the potential abnormalities and malfunctions of the cardiovascular system such as heart failure (Inan et al, 2018), hypovolemia (Tavakolian et al, 2014), and hypotension (Brubakk et al, 1987) or to validate cardiac resynchronization therapy (Marcus et al, 2007). Moreover, this technology can be used to monitor the improvement of cardiac performance in healthy individuals as a result of the adoption of a healthier and more active lifestyle.…”

Section: Discussionmentioning

confidence: 99%

“…Cardiac time intervals have clinical significance in mitral valve stenosis, coronary artery disease (Boudoulas, 1990; Reant et al, 2010), arterial hypertension (Brubakk et al, 1987), atrial fibrillation, hypovolemia and fluid responsiveness (Tavakolian et al, 2014), chronic myocardial disease (Reant et al, 2010) and in the assessment of left ventricular performance (Boudoulas, 1990; Reant et al, 2010). These intervals present a temporal description of the sequential phases of a cardiac cycle.…”

Section: Introductionmentioning

confidence: 99%

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Comparison of Different Methods for Estimating Cardiac Timings: A Comprehensive Multimodal Echocardiography Investigation

Dehkordi

Khosrow-Khavar²,

Rienzo

et al. 2019

Front. Physiol.

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Cardiac time intervals are important hemodynamic indices and provide information about left ventricular performance. Phonocardiography (PCG), impedance cardiography (ICG), and recently, seismocardiography (SCG) have been unobtrusive methods of choice for detection of cardiac time intervals and have potentials to be integrated into wearable devices. The main purpose of this study was to investigate the accuracy and precision of beat-to-beat extraction of cardiac timings from the PCG, ICG and SCG recordings in comparison to multimodal echocardiography (Doppler, TDI, and M-mode) as the gold clinical standard. Recordings were obtained from 86 healthy adults and in total 2,120 cardiac cycles were analyzed. For estimation of the pre-ejection period (PEP), 43% of ICG annotations fell in the corresponding echocardiography ranges while this was 86% for SCG. For estimation of the total systolic time (TST), these numbers were 43, 80, and 90% for ICG, PCG, and SCG, respectively. In summary, SCG and PCG signals provided an acceptable accuracy and precision in estimating cardiac timings, as compared to ICG.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Comparison of Different Methods for Estimating Cardiac Timings: A Comprehensive Multimodal Echocardiography Investigation

Dehkordi

Khosrow-Khavar²,

Rienzo

et al. 2019

Front. Physiol.

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“…This mortality rate is independent of the number of involved vessels. 26 Brubakk et al 27 stated that in the 1st month after myocardial infarction, a PEP/LVET ratio above 0.42 indicates a decrease in the 6-year survival rate. According to Stack et al, 28 a high PEP/LVET ratio in resting conditions is related to LV function and the degree of coronary stenosis and the number of involved vessels.…”

Section: Discussionmentioning

confidence: 99%

Effects of Afterload Increase on Systolic and Diastolic Functions of the Myocardium After Myocardial Infarction

Heper

2004

Angiology

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The evaluation of noninfarcted zone function after myocardial infarction by the use of noninvasive methods is very important. The authors speculated that phenylephrine, which increases systemic vascular resistance and blood pressure and has no effect on central ischemic and border-zone myocardium but does have an effect on remote myocardium, could be used as a stress agent as information is gathered about the functional capacity of the left ventricle and the status of coronary arteries in patients with recent myocardial infarction. Forty-six patients with recent myocardial infarction (5 women, 41 men; mean age: 53.6 +/-9.3 years) and 15 individuals with normal findings from coronary angiography and ventriculography (9 women and 6 men; mean age: 39.0 +/-11.2 years) were included in the study. The study was performed on the 4th or 5th day of the myocardial infarction. Preejection period/left ventricular ejection time (PEP/LVET), diastolic mitral flow velocity, isovolumic relaxation time (IVRT), and deceleration time (DT), were measured before and after the phenylephrine infusion, with M-mode, pulse wave, and continuous-wave echocardiography. After pressor stress with phenylephrine infusion, all the parameters were measured again. Coronary angiography and ventriculography were performed on all the patients on the 7th to 10th day of the myocardial infarction. All the patients were grouped according to their ejection fraction and the number of involved coronary arteries. The increase in the PEP/LVET ratio in Group 1 (left ventricle ejection fraction [EF] below 40%) and multivessel coronary artery lesion group was significant (p<0.01). PEP/LVET ratio decreased significantly in both Group C (patients with normal-appearing coronary arteries and ventriculographies) and the single-vessel coronary disease group. Although the early diastole flow/atrial systole flow (E/A) ratio increased significantly in the 3 groups, the 0.5 and more increase in E/A ratio had high sensitivity (86%) and specificity (80%) in differentiating the low EF group. The 0.5 and more increase in E/A ratio had 65% sensitivity and 69% specificity in differentiating the multivessel coronary stenosis group. A deceleration time of 130 msec and below in basal conditions had a high sensitivity (86%) and specificity (92%) for detecting the group in which EF was below 40%. After phenylephrine infusion, the shortening of IVRT was significant in Group 1 (p<0.01). Phenylephrine, which has been shown to be an alpha-1 receptor agonist in low doses and effective only on remote myocardial function, may be given with low complication rates in the early postinfarction period. The increase in PEP/LVET ratio, 0.5 and more increase in E/A ratio, and shortening of DT and IVRT after phenylephrine infusion may be indicators of low LV functional capacity and widespread coronary artery disease. This test may suggest performance of early invasive detection of coronary artery disease and early revascularization. This study may also be interesting from a pathophysiological point o...

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“…The study was a subproject of the Norwegian Multicenter Study on timolol after myocardial infarction [1], The methods and follow up have been described in detail elsewhere [1,7,9].…”

Section: Patient Groupsmentioning

confidence: 99%

“…The findings of the study indicate that the length of the diastole is a prognostic factor with respect to survival after acute myocardial infarction and that timolol has a lengthening effect on diastole beyond the effect of reduced HR. ß-Blocker treatment reduces mortality and reinfarc tion after acute myocardial infarction [1][2][3][4].The mechanism of this favorable effect is still under debate [5,6] and may depend on several factors, including control of hypertension, anti-ischemic effect, antiarrhythmogenic properties and antiplatelet effect.The ß-adrenergic blocking agent timolol has been found to preserve left ventricular function better than pla cebo treatment in patients treated for 1 year after acute myocardial infarction [7], Increased diastolic time (DT) has been proposed as a beneficial effect of propranolol in patients with coronary artery disease [8].This study was performed in order to: (1) evaluate DT in relation to mortality after acute myocardial infarction, and (2) study the duration of the diastole in patients treated with timolol after acute myocardial infarction, compared both to a placebo-treated group of patients and to a normal group of individuals. …”

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confidence: 99%

Diastolic Time in Patients Treated with Timolol or Placebo after Acute Myocardial Infarction

Brubakk¹,

Bergan²,

Pedersen³

et al. 1993

Am J Noninvas Cardiol

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β-Blockers reduce mortality after acute myocardial infarction. Prolongation of the diastole may be one favorable effect from ß-blockers. In this study, 55 patients were allocated to timolol treatment and 54 to placebo treatment after acute myocardial infarction. During follow-up, 26 patients died, 5 in the timolol and 21 in the placebo group. The patients were examined at baseline and after 1 and 12 months of treatment. Both at 1 and 12 months, diastolic time in percent of normal values (DT%) was significantly longer in the timolol than in the placebo group of patients (p = 0.0017 and 0.0067, respectively). The regression equations between DT and the R-R distance had a significantly steeper slope in the timolol than in the placebo group at 1 month (95% Cl -0.14 to -0.029). The total length of diastole per minute (heart rate, HR x DT) was significantly longer in the timolol group at 1 and 12 months (p < 0.0001). In the timolol group, DT% and total diastole were significantly longer in the survivors than in the nonsurvivors at the last registration (p = 0.0302 and 0.0012, respectively). In the placebo group, only total diastole was significantly longer in the survivors (p = 0.032). The findings of the study indicate that the length of the diastole is a prognostic factor with respect to survival after acute myocardial infarction and that timolol has a lengthening effect on diastole beyond the effect of reduced HR.

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Noninvasive evaluation of the effect of timolol on left ventricular performance after myocardial infarction and the consequence for prognosis

Cited by 8 publications

References 21 publications

Comparison of Different Methods for Estimating Cardiac Timings: A Comprehensive Multimodal Echocardiography Investigation

Comparison of Different Methods for Estimating Cardiac Timings: A Comprehensive Multimodal Echocardiography Investigation

Effects of Afterload Increase on Systolic and Diastolic Functions of the Myocardium After Myocardial Infarction

Diastolic Time in Patients Treated with Timolol or Placebo after Acute Myocardial Infarction

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