Handgrip Maneuver Research Articles

Afterload increase challenge unmasks systolic abnormalities in heart failure with preserved ejection fraction

Provocative maneuvers have the potential to overcome the low sensitivity of resting echocardiography and biomarkers in the detection of heart failure with preserved ejection fraction (HFpEF). We investigate the mechanical response of the left ventricle to an afterload challenge in patients with preclinical and early-stage HFpEF (es-HFpEF). Three groups of patients (non-HFpEF - n=42, pre-HFpEF - n=43, and es-HFpEF - n=39) underwent echocardiography at rest and during an afterload challenge induced by handgrip maneuver combined with pneumatic constriction of limbs. Patients in the non-HF group displayed a median ΔLPSS=-4% (IQR: -10%, +2%), LPSS rest<16% in 3/42(7%) and LPSS stress<16% in 6/43(14%). Subjects in the pre-HFpEF group displayed median ΔLPSS=-3% (IQR: -10%, +5%) LPSS rest<16% in 13/43(30%) and LPSS stress<16% in 19/43 (44%). 11/43 (25%) subjects in this group increased at least one absolute point in LPSS during stress. Patients in es-HFpEF group displayed a median ΔLPSS=-10% (IQR: -18%, -1%), LPSS rest<16% in 15/39(38%) and LPSS stress<16% in 25/39(64%). Changes in LPSS (ΔLPSS) were significantly greater in es-HFpEF than pre-HFpEF (p=0.022). In multivariate analysis, this group effect was maintained after adjustment of the LPSS for systolic blood pressure, use of β-blockers, LV mass, RWT, age, and sex. Our data suggest that patients with HFpEF have a marked decrease in peak strain during acute pressure overload. Longitudinal studies are needed to test and compare the clinical impact of each pattern in early and long-term follow-ups.

S-45-4: THE EFFECTS OF HANDGRIP STRESS TEST ON HEMODYNAMIC PARAMETERS IN PATIENTS WITH HYPERTENSION AND DIASTOLIC HEART FAILURE

Aim: The effectiveness of isometric handgrip exercise on changes of cardiovascular hemodynamic parameters in patients with diastolic heart failure is unknown. We assess the effect of several hemodynamic parameters and it changes during handgrip maneuvers in patients with arterial hypertension and diastolic heart failure during different stages of chemotherapy. Methods: The study population included 245 patients females /120 pts with HFpEF and 100 pts with HFmrEF and 25 pts with HFnEF / mean age of 45 years/. The effects of handgrip maneuver on hemodynamic parameters were studied by speckle tracking echocardiography. Following maximal squeeze until 100%, during the next 3 minutes patients were instructed to apply pressure at 50 %. The global longitudinal strain were extracted by 3, 4 and 2 CV images 70 fr/s and MAP and HR were performed at basal level, 1st, 2nd and 3rd minutes during handgrip stress test. Results: Heart rate (HR) and mean arterial pressures (MAP) increased significantly after handgrip maneuver (from 95 beats/min to 101 beats/min; from 109 mm Hg to 118 mm Hg, p &lt; 0.05 respectively). Pulmonary capillary wedge pressure (PCWP), pulmonary artery systolic (s) and diastolic (d) pressures (PAP), cardiac index (CI), left ventricular ejection fraction (LVEF), did not change after handgrip maneuvers (p &gt; 0.05). On the other hand, PAPs and PAPd, MAP and HR (p &lt; 0.05) decreased significantly during handgrip maneuvers in group with HFmrEF. In same group were found significantly decreases of GLVLS at 2nd and 3rd minutes during stress test comparable with other 2 groups / p &lt; 0.01/ Conclusion: Cardiovascular response to handgrip maneuver may be a marker of failure to respond to compensatory mechanisms. Patients with good LV reserve had a rise in stroke /work with little or no change in LVEDP. Patients with poor reserve had a fall in stroke/ work together with a substantial rise in LVEDP. It is concluded that the stress imposed by sustained handgrip provides a simple test for the evaluation of left ventricular reserve in patients, who will develop cardiotoxicity during chemotherapy treatment.

PS-C14-2: QUANTITATIVE METHODS FOR ASSESSING CONTRACTILE RESERVE IN PATIENTS WITH DIASTOLIC HEART FAILURE

Aim: The effectiveness of isometric handgrip exercise on changes of cardiovascular hemodynamical parameter in patients with diastolic heart failure is unknown. We assessed the effect of several hemodynamic parameters and it changes during handgrip maneuvers in patients with different stages of diastolic heart failure during chemotherapy and their improvements after 4 months follow up (4mFU) treatment with single pill combination of ACE inhibitor ACE) and beta blocker(BB). Methods: The study population included 65 patients female / mean age of 45 ± 12 years/ 55 with breast cancer and undergoing chemotherapy / 30 pts with HFpEF and 25 pts with HFmrEF / and 10 pts with HFnEF and without chemotherapy. The effect of handgrip maneuver on hemodynamic parameters were studied by speckle tracking echocardiography. Following maximal squeeze by 100%, during the next 3 minutes patients were instructed to apply pressure at 50%. The global longitudinal strain were extracted by 3, 4 and 2 chamber apical view images on 70 fr/s and MAP and HR were performed at basal level, 1st, 2nd and 3rd minutes during handgrip stress test. The contractility /force/ of LV were also calculate as ratio SBP / ESV. Patients with HFmrEF and HFpEF received for 4 months treatment with single pill combination ACE (perindorpril)/ BB (bisoprolol) 5/5 mg. Results: Heart rate(HR) and mean arterial pressure(MAP) increased significantly after handgrip maneuver / from 75 ± 6 beats /min to 101 ± 12 beats/ min, 109 ± 15 mmHg to 118 ± 19mmHg, p &lt; 0,05 /. Pulmonary artery systolic(s) and diastolic (d) pressure(PAP),pulmonary capillary wedge pressure (PCWP), cardiac index(CI), LVEF did not change significantly(p &gt; 0,5) after handgrip maneuvers. On the other hand, LV force (SBP/ ESV ratio),MAP and HR decreases significantly (p &lt; 0,01) in group with HFmrEF. In same group were found significantly decreased GLVLS at 2nd and 3rd minutes during stress- test comparable with other 2 groups with HFpEF and HFnEF. After 4mFU and treatment with 5/5 mg doses combination of ACE / BB were found improvement in parameters: HR /p &lt; 0,001/, MAP /p &lt; 0.01/ and contractile reserve as well as LV force /p &lt; 0, 01/ and GLVLS /p &lt; 0,001/. Conclusion: Cardiovascular response to handgrip maneuver may be a marker of failure to respond to compensatory mechanisms. Patients with good LV reserve had a rise in stroke work with little or no change in LVEDP. Patients with poor contractile reserve had a fall in stroke work reserve together with a substantial rise in LVEDP. It is concluded that the stress imposed by sustained handgrip provides a simple test for evaluation of LV contractile reserve in patients, who will develop cardiotoxicity during chemotherapy treatment. The treatment with combination with small doses ACE/BB is a big challenge in patients with HFmrEF and HFpEF to improve the contractile reserve.

Cardiovascular reactivity to stress shows proneness to future blood pressure status in students of a teaching hospital in Nepal

Stress is a condition that disrupts or threatens to disrupt homeostasis. Stress may be physical or mental. Physical stress includes exercise (isometric or isotonic), pain, temperature (too hot or cold) etc. The development of hypertension is usually preceded by a prehypertensive state that may be manifested by abnormal cardiovascular reactivity to different types of stress viz., mental stress, cold water immersion, isotonic exercise, isometric handgrip, and valsalva maneuver. In present study, we have used isometric handgrip (IHG) exercise, as a stressor, aiming to identify individuals at increased risk for developing hypertension at early life. Normotensive, non-smoker sedentary two hundred male subjects, one hundred each from normotensive and hypertensive families, of age group 18-25 years participated in the study as volunteers. The causal blood pressure and heart rate of the participants were recorded in the sitting position by using mercury sphygmomanometer and stethoscope. Then, the isometric handgrip (IHG) exercise demonstrated to each of them using handgrip dynamometer. Maximum voluntary contraction (MVC) was noted as maximum pressure (in Kg) sustained during three seconds of handgrip using a handgrip dynamometer. The participants were asked to sustain isometric handgrip at one third of MVC for one minute with the same instrument (handgrip dynamometer). Both blood pressure and heart rate were recorded immediately after 1 and 3 minutes following isometric handgrip (IHG) exercise. The data analyzed using t-test showed that diastolic blood pressure didn’t return and stabilized to pre-exercise level even after 3 minutes following exercise in volunteers who were mostly from hypertensive family. More number of volunteers with family history of hypertensive (24%) showed elevated diastolic blood pressure even after 3 minutes whereas a few of the volunteers (8%) with no family history of hypertension showed rise in DBP even after 3 minutes following isometric handgrip (IHG) exercise. This present study indicated that the individuals having family history of hypertension are prone to develop hypertension in their early life, therefore, must adopt the healthier life style like avoidance of alcohol, smoking, and practice yogic exercise.

The impact of isometric handgrip testing in left atrial reservoir function

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): Fundação Adib Jatene Background Speckle tracking echocardiography (STE) allows accurate quantification of left atrial (LA) strain, thus allowing assessment of all phases of LA function (reservoir, conduit and contraction). Alterations in LA strain occur before changes in LA volumes, enabling early detection of LA dysfunction. In particular, the peak of LA strain during the reservoir phase (LASr) seems to be of prognostic value in heart failure. LASr is essential to pool enough blood volume to fill the LV during the subsequent diastole. The main determinants of LA reservoir function include blood volume arriving from the right ventricle, LA relaxation, and LA compliance. Still, changes in atrioventricular plane movement during the ventricular systole have been considered an additional factor influencing LASr. The relative contribution of left ventricular afterload to LASr, however, has yet to be clearly defined. Purpose We aimed to study the LA function during changes in LV afterload induced by the handgrip maneuver in subjects without heart disease, applying LASr and strain curve shape analysis. Material and Methods We studied 31 subjects (47 ± 15 years) without evidence of heart disease. A comprehensive 2D echocardiography was performed. We recorded 3 beat clips with standard STE views of LV and LA in baseline conditions and then during pressure overload-induced by left handgrip (42 ± 8 kg) combined with simultaneous pneumatic constriction of the right arm and both lower limbs. The LV GLS and LASr were calculated offline by a blinded examinator using commercially available software. Furthermore, we extracted the raw data of the strain curves and post-processed these signals using custom software. The global curves were split into different cardiac cycle phases using the valve opening and closure times(Figure 1). Quadratic functions estimated strain curves during the ejection phase due to the acceleration involved in the phenomenon. Quadratic function linear coefficients, a component of strain rate, were used to assess the shape of deformation curves. Results The handgrip maneuver caused mild reductions in LV strain: GLS baseline –19.07 % (±0.27) vs GLS handgrip -18.58% (±0.26) p = 0.02 (Figure 2A and C). Conversely, the LASr did not present significant changes: LASr baseline 33.82% (±0.84) vs LASr handgrip 32.96% (±0.85) p= 0.18 (Figure 2B and C). For the analysis of the shape of strain curves, we obtained data from 29 subjects. We found significant differences in LV ejection linear coefficient (ELC): LV ELC baseline –158.30 (±8.52) vs LV ELC handgrip –144.62 (±8.02) p = 0.02. For LA reservoir linear coefficient (RLC), we also found significant differences: LA RLC baseline 240.30 (±17.19) vs LA RLC handgrip 212.61 (±15.62) p = 0.03 (Figure 2D). Conclusion(s) The left atrial reservoir function is affected by changes in LV afterload induced by the handgrip maneuver. Our data suggest that LV pressure overload mainly impact the shape of LA strain curve rather than LASr. Abstract Figure 1 Abstract Figure 2

522 Reduced sympatho-vagal responses to orthostatic stress in drug-naïve idiopathic restless legs syndrome

Abstract Introduction Restless legs syndrome (RLS) is a risk factor for cardiovascular disease (CVD). However, there are no electrophysiological biomarkers to assess this risk. This study aimed to evaluate the heart rate variability (HRV) and autonomic control of cardiovascular reflexes in the supine and standing positions in patients with RLS during wakefulness. Methods Fourteen drug-naïve RLS patients (12 women, 2 men; mean age: 42.14 ± 7.81 years) and 10 healthy controls underwent tests for blood pressure, heart rate when in the supine-rest and standing positions, deep breathing, and handgrip in controlled laboratory conditions. Five-minute R-R intervals in each position were collected and analyzed for HRV. Results Cardiovascular changes during deep breathing and isometric handgrip maneuvers were normal and similar between the two groups. The normalized unit of the low frequency component and low frequency/high frequency (LH/HF) ratio during standing were lower in the RLS patients than in the controls. LF/HF ratio responses during positional change from supine-rest to standing were significantly reduced in the RLS patients (RLS patients: mean ± SD, 2.94 ± 3.11; controls: 7.51 ± 5.58; P = 0.042). In Spearman’s rank correlation, ISI and PSQI were associated with HRV parameters. Conclusion The RLS patients showed reduced sympatho-vagal responses during positional change from supine-rest to standing during wakefulness, and RLS-related sleep disturbance was an important contributing factor for autonomic nervous system dysfunction. Reduced HRV responses during wakefulness might be a good predictor for CVD risk. Support (if any):

QUANTITATIVE METHODS FOR ASSESSING CONTRACTILE RESERVE IN PATIENTS WITH HYPERTENSION AND DIASTOLIC HEART FAILURE

Objective: We assessed the effect of several hemodynamic parameters and it changes during handgrip maneuvers in patients with different stages of diastolic heart failure during chemotherapy and their improvements after 4 months follow up (4mFU) treatment with single pill combination of ACE inhibitor ACE) and beta –blocker (BB). Design and method: The study population included 65 patients- female / mean age of 45 ± 12 years/ 55 with breast cancer and undergoing chemotherapy / 30 pts with HFpEF and 25 pts with HFmrEF / and 10 pts with HFnEF and without chemotherapy. Following maximal squeeze by 100%, during the next 3 minutes patients were instructed to apply pressure at 50%. The global longitudinal strain and MAP and HR were performed at basal level, 1st, 2nd and 3rd minutes during handgrip stress test. The contractility /force/ of LV were also calculate as ratio SBP / ESV. Results: Heart rate (HR) and mean arterial pressure (MAP) increased significantly after handgrip maneuver / from 75 ± 6 beats /min to 101 ± 12 beats/ min, 109 ± 15 mmHg to 118 ± 19 mmHg, p &lt; 0,05 /. Pulmonary artery systolic(s) and diastolic (d) pressure (PAP),pulmonary capillary wedge pressure (PCWP), cardiac index (CI), LVEF did not change significantly (p &gt; 0,5) after handgrip maneuvers. On the other hand, LV force (SBP/ ESV ratio), MAP and HR decreases significantly (p &lt; 0,01) in group with HFmrEF. In same group were found significantly decreased GLVLS at 2nd and 3rd minutes during stress- test comparable with other 2 groups with HFpEF and HFnEF. After 4mFU and treatment with 5/5 mg doses combination of ACE / BB were found improvement in parameters: HR /p &lt; 0,001/, MAP /p &lt; 0.01/ and contractile reserve as well as LV force /p &lt; 0, 01/ and GLVLS /p &lt; 0,001/. Conclusions: Patients with good LV reserve had a rise in stroke –work with little or no change in LVEDP. Patients with poor contractile reserve had a fall in stroke- work reserve together with a substantial rise in LVEDP. The treatment with combination with small doses ACE/BB is a big challenge in patients with HFmrEF and HFpEF to improve the contractile reserve.

Auxiliary Tests of Autonomic Functions.

The autonomic nervous system is a complex neural network that controls several organ systems. Its assessment includes a detailed history of autonomic functions, clinical examination, and autonomic tests. Most widely used is a battery of tests that assess cardiovascular reflex autonomic and sudomotor tests, which include deep breathing (assesses parasympathetic function), Valsalva maneuver, tilt test (both assess parasympathetic and adrenergic functions), and sudomotor testing for the evaluation of postganglionic sudomotor fibers. These basic tests represent a foundation of autonomic testing. Nevertheless, the autonomic nervous system also controls organ systems not directly assessed by basic tests. This review describes a number of auxiliary autonomic tests that can be used in addition to basic autonomic tests or can be used independently to explore particular autonomic functions or to answer a specific clinical question. The auxiliary tests described in this review evaluate cardiovascular, thermoregulatory, gastrointestinal, genitourinary, eye, and exocrine functions. These tests are cold pressor test, sustained handgrip maneuver, reverse tilt test, venoarteriolar reflex, laser Doppler flare imaging, microneurography, neck suction, lower body negative pressure, venous occlusion plethysmography, pharmacologic assessment of postganglionic sympathetic outflow, plasma norepinephrine, sympathetic skin response, video cinefluoroscopic swallowing test, esophageal manometry test, small bowel manometry test, wireless motility capsule test, urodynamic studies, penile plethysmography, intracavernosal papaverine injection, infrared video pupillography, corneal confocal microscopy, pupillary response to dilute pilocarpine and hydroxyamphetamine, Schirmer test, tear osmolarity test, and salivary secretion test. The protocol of each test is described in detail. This review can be used as a quick reference for the auxiliary autonomic tests.

66 Simple bedside cardiovascular autonomic examinations for predicting chronotropic incompetence

Abstract Background Simple bedside cardiovascular autonomic reflex test (CARTs) are usually used to determine cardiovascular autonomic neuropathy (CAN). CAN may contribute to chronotropic incompetence (CI) which is the inability of the heart rate (HR) to rise in proportion to an increase in metabolic demand. Determination of CI is widely based on measurement of maximum HR during exercise testing. This study aimed to evaluate the role of CARTs to determine CI. Methods We included in 105 patients using a derivation and validation sampling ratio of 2:1. CARTs were performed for analyzing heart rate variation during three parasymphathetic standard tests (deep breathing, lying to standing, Valsava maneuver) and two sympathetic standard tests (systolic blood pressure from lying to standing and diastolic blood pressure during handgrip maneuver). Variables independently associated with CI in multivariable analysis in the derivation set were assigned points based on their respective odds ratios. Results CI group showed significantly lower values of among three parasympathetic standard tests (p &amp;lt; 0.05) but not significantly among two sympathetic standars tests. Valsava maneuver (OR 0.1, p &amp;lt; 0.001, 95%CI 0.001-0.004), deep breathing (OR 0.91, p = 0.025, 95% CI 0.836-0.988), and handgrip maneuver (OR 0.85, p = 0.01, 95% CI 0.744-0.961) were found to be an independent risk factor for CI from multivariate regression analysis. The accuracy of different CART parameters in the prediction of CI was described by the receiver operating curve (ROC) analysis. Regarding logistic regression model, we constructed formula of 15 - ([12 x Valsava maneuver] + [0.1 x deep breathing] + [0.2 x handgrip maneuver]) which will show negative and positive results indicating CI and non-CI, respectively. The resulting score showed good calibration and discriminatory capacity in the derivation (Hosmer-Lemeshow x² 10.051, p = 0.186, AUC = 0.878). The difference between AUCs in the derivation and validation sets was Δ = 0.122 (p = 0.174). Conclusion The decrease in heart rate variations during Valsava maneuver and deep breathing and in diastolic blood pressure during handgrip maneuver seems to be related to development of CI. Formula of CARTs score is a useful tool for predicting CI. Final score sheet based on formula Total score CI probability &amp;lt;-0.1 High probaility 0.2-0.6 Intermediate probability &amp;gt;0.6 Low probability

P972 Quantitative methods for assessing contractile reserve in patients with diastolic heart failure

Abstract Aim The effectiveness of isometric handgrip exercise on changes of cardiovascular hemodynamics parameter in patients with diastolic heart failure is unknown. We assessed the effect of several hemodynamic parameters and it changes during handgrip maneuvers in patients with different stages of diastolic heart failure during chemotherapy and their improvements after 4 months follow up (4mFU) treatment with single pill combination of ACE inhibitor ACE) and beta –blocker(BB) .Methods: The study population included 65 patients- female / mean age of 45 ± 12 years/ 55 with breast cancer and undergoing chemotherapy / 30 pts with HFpEF and 25 pts with HFmrEF / and 10 pts with HFnEF and without chemotherapy.The effect of handgrip maneuver on hemodynamic parameters were studied by speckle tracking echocardiography. Following maximal squeeze by 100%, during the next 3 minutes patients were instructed to apply pressure at 50%. The global longitudinal strain were extracted by 3, 4 and 2 chamber apical view images on 70-85 fr/s and MAP and HR were performed at basal level, 1st, 2nd and 3rd minutes during handgrip stress test. The contractility /force/ of LV were also calculate as ratio SBP / ESV . Patients with HFmrEF and HFpEF received for 4 months treatment with single pill combination ACE (perindorpril)/ BB (bisoprolol) 5/5 mg.Results:Heart rate(HR) and mean arterial pressure(MAP) increased significantly after handgrip maneuver / from 75 ±6 beats /min to 101 ±12 beats/ min, 109 ± 15 mmHg to 118 ± 19mmHg, p &amp;lt; 0,05 / .Pulmonary artery systolic(s) and diastolic (d) pressure(PAP),pulmonary capillary wedge pressure (PCWP) , cardiac index(CI) , LVEF did not change significantly(p &amp;gt; 0,5) after handgrip maneuvers . On the other hand, LV force (SBP/ ESV ratio) ,MAP and HR decreases significantly (p &amp;lt; 0,01) in group with HFmrEF. In same group were found significantly decreased GLVLS at 2nd and 3rd minutes during stress- test comparable with other 2 groups with HFpEF and HFnEF. After 4mFU and treatment with 5/5 mg doses combination of ACE / BB were found improvement in parameters: HR /p &amp;lt; 0,001/, MAP /p &amp;lt; 0.01/ and contractile reserve as well as LV force /p &amp;lt; 0, 01/ and GLVLS /p &amp;lt; 0,001/.Conclusion: Cardiovascular response to handgrip maneuver may be a marker of failure to respond to compensatory mechanisms. Patients with good LV reserve had a rise in stroke –work with little or no change in LVEDP. Patients with poor contractile reserve had a fall in stroke- work reserve together with a substantial rise in LVEDP. It is concluded that the stress imposed by sustained handgrip provides a simple test for evaluation of LV contractile reserve in patients, who will develop cardiotoxicity during chemotherapy treatment. The treatment with combination with small doses ACE/BB is a big challenge in patients with HFmrEF and HFpEF to improve the contractile reserve.

Abstract 17612: Hypertension Severity is Associated With Impaired Cognitive Performance

B: Hypertension affects the target-organs diversely. Most evidence on target-organ damage in hypertension is related to kidney and heart. The cerebrovascular and cognitive impairment are less studied. O: To study the cognitive function changes in patients with hypertension on different stages compared to the control pairs and their correlation with the arterial stiffness properties assessed by non-invasive methods and cerebral circulation assessed by transcranial Doppler. M: In a cross sectional study 162 patients (42 controls and 120 hypertensive) were comparatively evaluated. Hypertensive patients were divided in three stages according to the blood pressure levels or medication use (HTN-1: BP 140-159/90-99 or use of one antihypertensive drug; HTN-2: BP 160-179/100-109 or use of two drugs and HTN-3: BP ≥180/110 or use of three or more drugs). The following variables were evaluated: pulse wave velocity, intima medial thickness, cerebral blood flow velocities by transcranial Doppler (TD) and cognitive function. Mean velocity of middle cerebral artery was continuously monitored at resting and during the breath holding test (30 seconds) and 3 minutes handgrip maneuver. Cognitive function was assessed by mini mental state examination and Montreal Cognitive Assessment. R: Compared to control group, HTN-3 group was older, had higher BMI, IMT and PWV and lower educational level and family income (Table 1). Interestingly, the higher the hypertension stage the poorer was the performance in cognitive tests even after age correction. There was no difference among the groups related to TD velocities at rest and the hand-grip maneuver. However, it was noted a lower breath holding index in the hypertensive group (HTN-1=0.94±0.56; HTN-3=0.97±0.59 vs Control=1.5±0.68; p=0.002) which could infer less vasomotor reactivity in these patients. C: Cognitive impairment was more frequent in patients with hypertension and this frequency was related to hypertension severity.

Exercise-Induced Muscle Vasodilatation and Treadmill Exercise Test Responses in Individuals without Overt Heart Disease

Background: The beneficial effects of exercise on cardiovascular health may be related to the improvement in several physiologic pathways, including peripheral vascular function. The aim of this study was to evaluate the relationship between cardiovascular responses during the treadmill exercise test and exercise-induced muscle vasodilatation in individuals without overt heart disease. Methods: The study included 796 asymptomatic subjects (431 females and 365 males) without overt heart disease. We evaluated the heart rate (chronotropic reserve and heart rate recovery), blood pressure (maximum systolic and diastolic blood pressure as well as systolic blood pressure recovery) and exercise capacity during symptom-limited treadmill exercise testing. Exercise-induced muscle vasodilatation was studied with venous occlusion plethysmography and estimated by forearm blood flow and vascular conductance responses during a 3-min handgrip maneuver. Results: Forearm blood flow increase during the handgrip exercise was positively associated with heart rate recovery during treadmill exercise testing (p < 0.001). Forearm vascular conductance increase during the handgrip exercise was inversely associated with exercise diastolic blood pressure during exercise treadmill testing (p = 0.038). No significant association was found between exercise capacity and exercise-induced muscle vasodilation. Conclusion: In a sample of individuals without overt heart disease, exercise-induced muscle vasodilatation was associated with heart rate and blood pressure responses during treadmill exercise testing, but was not associated with exercise capacity. These findings suggest that favorable hemodynamic and chronotropic responses are associated with better vasodilator capacity, but exercise capacity does not predict muscle vasodilatation.

Dynamic Cerebral Autoregulation Changes during Sub-Maximal Handgrip Maneuver

PurposeWe investigated the effect of handgrip (HG) maneuver on time-varying estimates of dynamic cerebral autoregulation (CA) using the autoregressive moving average technique.MethodsTwelve healthy subjects were recruited to perform HG maneuver during 3 minutes with 30% of maximum contraction force. Cerebral blood flow velocity, end-tidal CO2 pressure (PETCO2), and noninvasive arterial blood pressure (ABP) were continuously recorded during baseline, HG and recovery. Critical closing pressure (CrCP), resistance area-product (RAP), and time-varying autoregulation index (ARI) were obtained.ResultsPETCO2 did not show significant changes during HG maneuver. Whilst ABP increased continuously during the maneuver, to 27% above its baseline value, CBFV raised to a plateau approximately 15% above baseline. This was sustained by a parallel increase in RAP, suggestive of myogenic vasoconstriction, and a reduction in CrCP that could be associated with metabolic vasodilation. The time-varying ARI index dropped at the beginning and end of the maneuver (p<0.005), which could be related to corresponding alert reactions or to different time constants of the myogenic, metabolic and/or neurogenic mechanisms.ConclusionChanges in dynamic CA during HG suggest a complex interplay of regulatory mechanisms during static exercise that should be considered when assessing the determinants of cerebral blood flow and metabolism.

Noninvasive and Nonocclusive Blood Pressure Estimation Via a Chest Sensor

The clinical demand for a device to monitor blood pressure (BP) in ambulatory scenarios with minimal use of inflation cuffs is increasing. Based on the so-called pulse wave velocity (PWV) principle, this paper introduces and evaluates a novel concept of BP monitor that can be fully integrated within a chest sensor. After a preliminary calibration, the sensor provides nonocclusive beat-by-beat estimations of mean arterial pressure (MAP) by measuring the pulse transit time (PTT) of arterial pressure pulses travelling from the ascending aorta toward the subcutaneous vasculature of the chest. In a cohort of 15 healthy male subjects, a total of 462 simultaneous readings consisting of reference MAP and chest PTT were acquired. Each subject was recorded at three different days: D, D+3, and D+14. Overall, the implemented protocol induced MAP values to range from 80 ± 6 mmHg in baseline, to 107 ± 9 mmHg during isometric handgrip maneuvers. Agreement between reference and chest-sensor MAP values was tested by using intraclass correlation coefficient (ICC = 0.78) and Bland-Altman analysis (mean error = 0.7 mmHg, standard deviation = 5.1 mmHg). The cumulative percentage of MAP values provided by the chest sensor falling within a range of ±5 mmHg compared to reference MAP readings was of 70%, within ±10 mmHg was of 91%, and within ±15 mmHg was of 98%. These results point at the fact that the chest sensor complies with the British Hypertension Society requirements of Grade A BP monitors, when applied to MAP readings. Grade A performance was maintained even two weeks after having performed the initial subject-dependent calibration. In conclusion, this paper introduces a sensor and a calibration strategy to perform MAP measurements at the chest. The encouraging performance of the presented technique paves the way toward an ambulatory compliant, continuous, and nonocclusive BP monitoring system.

On systolic murmurs and cardiovascular physiological maneuvers

Physiological principles that directly apply to physical diagnosis provide opportune occasions to bring basic science to the bedside. In this article, we describe the effect of cardiac maneuvers on systolic murmurs and how physiological principles apply to the explanation of the changes noted at the bedside. We discuss the effect of Valsalva, squatting, and hand grip maneuvers on different physiological parameters influencing preload, afterload, chamber dimensions, and pressure gradients. The clinical manifestations noted during the aforementioned maneuvers are described in common cardiac conditions responsible for the production of certain systolic murmurs.

Gerbode ventricular septum defect covered by a ballooning membranous ventricular septum

A 55-year-old man was admitted due to a new cardiac murmur diagnosed by his general practitioner during check-up. The patient was asymptomatic and denied chest pain or dyspnea. Physical examination revealed a grade 3/6 holosystolic heart murmur at the left sternal border with increased intensity to handgrip maneuvers. In addition, mild edema was present at his ankles up to mid of the lower legs that the patient himself had not recognized before. Electrocardiogram, blood sample, and cardiac markers were unremarkable. Transthoracic echocardiography (TTE) revealed enlargement of heart chambers with normal systolic ventricular function and elevated pulmonary pressure. In addition, a cystic thin walled structure was seen with adhesion at the septal tricuspid valve ring that yo-yoed between the right atrium (RA) and the right ventricle (RV) like a table tennis ball. Colour Doppler echocardiography showed a complete systolic filling of this structure. Diagnostic work-up revealed a congenital defect of subaortic perimembranous ventricle septum (VSD) with conjunction between left ventricle (LV) and RA, a so-called Gerbode-VSD, covered by a prolapsing cystic formation of 38 9 29 9 27 mm (Figs. 1, 2). By MRI and heart catheterization, a relevant left-to-right shunt of 1:2 was measured. Hemodynamic parameters are given in Table 1. MRI confirmed a perforation of the cystic sack causing the shunt with direct flow to RA (Fig. 2b). Surgery under cardiopulmonary bypass was undertaken and revealed a right sided whitish cystic mass typical for a large diverticulum of the membranous ventricular septum with basis above the tricuspid valve and riding above a Gerbode-VSD of 6 mm. Opposite to the VSD, the cystic structure was perforated resulting in a direct communication between LV and RA (Figs. 2b and 3a, b). The diverticulum was removed, VSD was closed with a bovine pericardial patch and the tricuspid valve was successfully reconstructed. Pathohistologic inspection of the cystic structure showed endoand myocardium with fibrotic and sclerotic conversion and only mild chronic inflammatory reaction (Fig. 3c). Patient was discharged in stable conditions 10 days after surgery. The specific feature of our patient is the coverage of the Gerbode-VSD by the expanded membranous ventricular septum protruding into the RA with extension through the tricuspid valve during heart cycle. A small rupture of the cystic formation caused a nearly indirect shunt between LV and RA. Shunts between LV and RA are rare forms of VSD and can be either congenital or acquired. They were first described in 1857 and represent \1 % of all congenital cardiac defects [1]. The surgeon Frank Gerbode at Stanford had published the first successful series of patients operated on a LV–RA shunt in 1958 [2]. Acquired defects can occur secondarily after bacterial endocarditis, trauma, myocardial infarction, repair or replacement of either the mitral or aortic valves or are reported after catheter ablation of the atrioventricular node [1, 3–7] and are diagnosed using varying U. M. Muller (&) U. Pittl G. C. Schuler Department of Internal Medicine/Cardiology, Heart Center, University of Leipzig, Strumpellstrase 39, 04289 Leipzig, Germany e-mail: ulrike.mueller@herzzentrum-leipzig.de

Retrograde flow components in the brachial artery. A new hemodynamic index

Arm elevation induces diastolic retrograde flow in the brachial artery and an incremental rise in arterial compliance in healthy subjects with no modifications in vascular resistance. In contrast, changes in resistance have been observed after handgrip exercise. Our objective was to investigate if the resistance change induced by isometric handgrip exercise is able to reverse diastolic retrograde flow induced by arm elevation in a healthy population and to explore these adaptive changes in hypertensive subjects. Arterial flow velocity Doppler measurements were obtained including: (a) a baseline measurement, (b) measurement 30 s after arm elevation, (c) measurement during handgrip maneuver with the arm elevated, (d) measurement during handgrip release with the arm elevated. Our findings showed that diastolic retrograde flow is induced by arm elevation, partially increased by arm-up handgrip and completely reversed during arm-up handgrip release both in healthy and hypertensive subjects. As compared with normal subjects, deceleration time was longer in the hypertensive subjects during baseline but not during the arm-up stage, handgrip contraction and handgrip release stages. An important increase in deceleration time values from baseline to arm-up and handgrip contraction stages was observed in normal subjects but not in the hypertensive group. We believe that the highly significant difference in reactivity to postural changes observed in deceleration time values constitutes a promising hemodynamic index to investigate. Also, our observation of complete reversal of the retrograde flow during arm-up handgrip release provides a new approach to postural and exercise-induced vasomotor responses.

Evaluation of early and late postoperative flow capacity of internal thoracic artery bypass by means of stress Doppler echocardiography

Arterial revascularization with the internal thoracic artery (ITA) has shown exceptional long-term results, even though early hypoperfusion can occur and can cause ischemia and contractile dysfunction. Therefore, it is still controversial as to whether the bypass vessel can guarantee the required demand for blood flow during the early postoperative (EPO) phase or whether this is only possible a long time after the operation. This question is important particular in the early postoperative phase to manage afterload and reduce left ventricular oxygen demand. Therefore, stress Doppler echocardiography was performed to assess EPO and late postoperative (LPO) flow capacity after minimal-invasive coronary artery bypass grafting (MIDCAB) in subjects with single vessel disease. Doppler echocardiography was performed after MIDCAB in 15 patients (mean age 65 years+/-12 standard deviation) in the EPO (15 days) and LPO (266 days) at rest and under stress. The mean diastolic velocity (MDV) as a measure for the coronary perfusion in the bypass-graft was comparable (30.9+/-14.5 EPO to 30.8+/-13.9 cm/s LPO, P>0.05) for both settings (early vs. late). In both tests, the stress reactions by means of handgrip maneuver lead to comparable increases in blood flow: MDV 65.0+/-54.4% (EPO) to 62.5+/-53.7% n.s. (LPO). The flow increase in the bypass graft was just as similar [48.2+/-46.2% (EPO) to 51.1+/-41.6% n.s. (LPO)]. The stress echocardiography revealed for the first time that the ITA-graft after MIDCAB-operation is able to produce the same flow reserve through the EPO phase as well as the LPO phase. Restrictions to a maximum early flow adaptation are not justified. Thus, particularly a patient with severe comorbidities or higher age should be mobilized in the EPO phase to minimize the postoperative complications without risk of myocardial ischemia caused by impaired early blood flow through recent implanted ITA. This method for assessment of ITA blood flow allows for long-time observations and can detect disturbances in perfusion at an early stage.

Influence of demographic and metabolic variables on forearm blood flow and vascular conductance in individuals without overt heart disease

Vascular reactivity is involved in the regulation of vascular function either in normal conditions or in the pathophysiology of cardiovascular diseases. We tested the hypothesis that vascular reactivity evaluated by forearm blood flow may vary according to demographic and metabolic variables in a cohort of individuals without any evidence of heart disease after clinical examination. We studied 186 individuals (mean age 41.4 years, standard deviation 13.1 years; 95 (51%) men and 91 (49%) women. We investigated forearm blood flow and vascular conductance with venous occlusion plethysmography at baseline, during handgrip isometric exercise and during the recovery phase. Demographic and laboratory data were collected. Statistical analysis was performed with mixed linear models appropriate for repeated measurements. Mean forearm blood flow values in the different study conditions ranged between 1.7+/-0.47 mL.min(-1).100 mL(-1) of tissue and 2.82+/-1.13 mL.min(-1).100 mL(-1) of tissue. Forearm blood flow was higher in men than in women (P<0.005) and increased as the heart rate increased during handgrip maneuver (P<0.0001). Serum triglyceride levels were inversely related to forearm blood flow at baseline, during isometric exercise and recovery phase (P=0.0209). Body mass index was inversely related to forearm vascular conductance at baseline, during isometric exercise and recovery phase (P=0.0223). Our findings suggest that forearm blood flow and vascular conductance as a surrogate of the vascular function may be influenced by gender, heart rate, serum triglyceride levels and body mass index in individuals without overt heart disease.

Effects of N‐acetylcysteine on glutathione oxidation and fatigue during handgrip exercise

Fatigue of hand and forearm muscle groups can limit task performance by astronauts wearing space suits. Countermeasures to delay fatigue would therefore be useful to the space program. N-acetylcysteine (NAC) has been shown to inhibit fatigue during other tasks so we tested its effects during handgrip exercise. Volunteers practiced isometric handgrip maneuvers until performance was reproducible over three successive sessions (baseline). Performance then was retested after ingesting NAC (150 mg.kg(-1)) or saline. Drug administration increased NAC and cysteine blood levels (P < 0.001). Performance of sustained maximal efforts was unaffected. During repetitive submaximal efforts, NAC delayed fatigue (130% baseline) and inhibited glutathione oxidation. Saline did not alter glutathione status or performance of sustained maneuvers; repetitive task performance was increased by 15% (P < 0.05), a placebo effect. These data indicate that NAC supports glutathione homeostasis in exercising humans and may delay muscle fatigue during repetitive handgrip exercise. Our findings support oxidative stress as a causal factor in human muscle fatigue and argue for larger translational studies to define NAC effects on human performance.