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Silber HA, Gilotra NA, Miller TL. Noninvasive Point of Care Device for Assessing Cardiac Response to Acute Volume Changes. MEDICAL DEVICES-EVIDENCE AND RESEARCH 2023; 16:219-227. [PMID: 37908436 PMCID: PMC10614661 DOI: 10.2147/mder.s416845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 10/04/2023] [Indexed: 11/02/2023] Open
Abstract
Purpose The change in the amplitude of a peripheral pulse in response to a Valsalva maneuver has diagnostic utility for assessing volume status at the bedside. We have developed a device to automatically quantify the Valsalva pulse response (VPR) to a standardized Valsalva maneuver that the device guides a user to perform. In this study, we sought to determine whether VPR by the device, Indicor, is sensitive enough to detect the acute increase in central pressure and volume load that occurs with a passive leg raise (PLR) in healthy volunteers. Methods Healthy volunteers were tested semirecumbently at 45 degrees, then again after being leaned back on a pivoted wedge with legs raised at 45 degrees and torso and head flat, and then again in the semirecumbent position. The device recorded a finger photoplethysmography (PPG) signal during a 10-second expiratory effort of 20 mmHg as guided by the device. VPR was automatically calculated as the ratio of the end-Valsalva pulse amplitude to the baseline pulse amplitude. Results In the 30 participants who completed testing, VPR increased from baseline to PLR in every participant, from 0.34 ± 0.13 to 0.60 ± 0.14 (p < 0.0001). Back upright, VPR decreased back to 0.33 ± 0.10 (p < 0.0001 versus PLR; NS versus baseline position). Conclusion In this proof-of-concept study of healthy participants, the Indicor device, a noninvasive, convenient device that automatically calculates VPR from a finger photoplethysmography signal during a standardized Valsalva maneuver, was sensitive enough to detect the increase in VPR that occurred with an acute central volume load from a PLR. Future studies should examine whether VPR responds differently to a PLR in heart failure patients with abnormal cardiac performance and/or congestion.
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Affiliation(s)
- Harry A Silber
- Department of Medicine, Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Nisha A Gilotra
- Department of Medicine, Division of Cardiology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Thomas L Miller
- Enalare Therapeutics, Inc, Princeton, NJ, USA
- Department of Pediatrics, Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
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2
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Özen Kavas P, Recep Bozkurt M, Kocayiğit İ, Bilgin C. Machine learning-based medical decision support system for diagnosing HFpEF and HFrEF using PPG. Biomed Signal Process Control 2023. [DOI: 10.1016/j.bspc.2022.104164] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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3
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Fathieh F, Paak M, Khosousi A, Burton T, Sanders WE, Doomra A, Lange E, Khedraki R, Bhavnani S, Ramchandani S. Predicting cardiac disease from interactions of simultaneously-acquired hemodynamic and cardiac signals. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 202:105970. [PMID: 33610035 DOI: 10.1016/j.cmpb.2021.105970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 02/01/2021] [Indexed: 06/12/2023]
Abstract
BACKGROUND AND OBJECTIVE Coronary artery disease (CAD) and heart failure are the most common cardiovascular diseases. Non-invasive diagnostic testing for CAD requires radiation, heart rate acceleration, and imaging infrastructure. Early detection of left ventricular dysfunction is critical in heart failure management, the best measure of which is an elevated left ventricular end-diastolic pressure (LVEDP) that can only be measured using invasive cardiac catheterization. There exists a need for non-invasive, safe, and fast diagnostic testing for CAD and elevated LVEDP. This research employs nonlinear dynamics to assess for significant CAD and elevated LVEDP using non-invasively acquired photoplethysmographic (PPG) and three-dimensional orthogonal voltage gradient (OVG) signals. PPG (variations of the blood volume perfusing the tissue) and OVG (mechano-electrical activity of the heart) signals represent the dynamics of the cardiovascular system. METHODS PPG and OVG were simultaneously acquired from two cohorts, (i) symptomatic subjects that underwent invasive cardiac catheterization, the gold standard test (408 CAD positive with stenosis≥ 70% and 186 with LVEDP≥ 20 mmHg) and (ii) asymptomatic healthy controls (676). A set of Poincaré-based synchrony features were developed to characterize the interactions between the OVG and PPG signals. The extracted features were employed to train machine learning models for CAD and LVEDP. Five-fold cross-validation was used and the best model was selected based on the average area under the receiver operating characteristic curve (AUC) across 100 runs, then assessed using a hold-out test set. RESULTS The Elastic Net model developed on the synchrony features can effectively classify CAD positive subjects from healthy controls with an average validation AUC=0.90±0.03 and an AUC= 0.89 on the test set. The developed model for LVEDP can discriminate subjects with elevated LVEDP from healthy controls with an average validation AUC=0.89±0.03 and an AUC=0.89 on the test set. The feature contributions results showed that the selection of a proper registration point for Poincaré analysis is essential for the development of predictive models for different disease targets. CONCLUSIONS Nonlinear features from simultaneously-acquired signals used as inputs to machine learning can assess CAD and LVEDP safely and accurately with an easy-to-use, portable device, utilized at the point-of-care without radiation, contrast, or patient preparation.
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Affiliation(s)
- Farhad Fathieh
- CorVista Health(†), 160 Bloor St. East, Suite 910, Toronto, ON, Canada
| | - Mehdi Paak
- CorVista Health(†), 160 Bloor St. East, Suite 910, Toronto, ON, Canada
| | - Ali Khosousi
- CorVista Health(†), 160 Bloor St. East, Suite 910, Toronto, ON, Canada
| | - Tim Burton
- CorVista Health(†), 160 Bloor St. East, Suite 910, Toronto, ON, Canada
| | - William E Sanders
- CorVista Health, Inc., 401 Harrison Oaks Blvd, Suite 100, Cary, NC, USA
| | - Abhinav Doomra
- CorVista Health(†), 160 Bloor St. East, Suite 910, Toronto, ON, Canada
| | - Emmanuel Lange
- CorVista Health(†), 160 Bloor St. East, Suite 910, Toronto, ON, Canada
| | - Rola Khedraki
- Division of Cardiovascular Medicine, Healthcare Innovation Laboratory, Scripps Clinic, San Diego, CA, USA
| | - Sanjeev Bhavnani
- Division of Cardiovascular Medicine, Healthcare Innovation Laboratory, Scripps Clinic, San Diego, CA, USA
| | - Shyam Ramchandani
- CorVista Health(†), 160 Bloor St. East, Suite 910, Toronto, ON, Canada.
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Silber HA, Win TT, Monti J, Galiatsatos P. Quantifying changes in size of arrhythmic photoplethysmography waveforms during a Valsalva maneuver for assessing cardiac filling pressure. Physiol Meas 2020; 41:105004. [PMID: 33164916 DOI: 10.1088/1361-6579/abb790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
OBJECTIVE We previously showed that the change in amplitude of a finger photoplethysmography waveform during the Valsalva maneuver reflects cardiac filling pressure. However, the automated determination of peaks and valleys to calculate amplitude is limited in significant arrhythmias such as atrial fibrillation and premature ventricular complexes, which are common in heart failure. The purpose of this study was to assess the change in size of the waveform by calculating the change in root mean square (RMS) of the signal, thereby utilizing the entire cardiac cycle, and to compare it to change in size of peak-to-valley amplitude. APPROACH We compared the two approaches in signals obtained from participants of a prior study who were tested prior to a clinically indicated cardiac catheterization. Correlation between the two methods was assessed in cases without, and then with, significant arrhythmias including atrial fibrillation or premature ventricular complexes. MAIN RESULTS Calculations from the two methods of peak-valley amplitude and RMS were highly correlated with each other in signals without (0.99, p < 0.0001, n = 252) and with significant arrhythmias (0.90, p < 0.0001, n = 34). SIGNIFICANCE RMS analysis of photoplethysmography signal size during the Valsalva maneuver is highly correlated with the method of analyzing changes in peak-valley amplitude, but does not rely on identifying peaks and valleys. The RMS method may be a more robust automated method of assessing cardiac filling pressure in patients with significant arrhythmias.
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Affiliation(s)
- Harry A Silber
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States of America
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Elias SO, Ajayi RE. Effect of sympathetic autonomic stress from the cold pressor test on left ventricular function in young healthy adults. Physiol Rep 2020; 7:e13985. [PMID: 30659769 PMCID: PMC6339552 DOI: 10.14814/phy2.13985] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 12/23/2018] [Accepted: 12/28/2018] [Indexed: 01/02/2023] Open
Abstract
There is a dearth of studies investigating the effect of sympathetic activation on left ventricular function. This study aimed to investigate the effect of sympathetic autonomic stress on left ventricular function in young healthy adults. Fifty‐six normotensive healthy participants (age 23.55 ± 3.82 years) took part in the study after giving informed consent. After obtaining baseline measurements, heart rate (HR), blood pressure (BP), peripheral saturation of oxygen (SpO2) and left ventricular function (assessed by means of ejection fraction (EF) obtained by transthoracic 2‐D echocardiography) were determined before and following sympathetic activation using cold pressor test (CPT). Exposure to CPT led to significant increase (P < 0.0001) in HR (70.4 ± 10.7 bpm to 91.6 ± 14.8 bpm), SBP (118 ± 8 mmHg to 138 ± 14 mmHg) and DBP (71 ± 7 mmHg to 91 ± 11 mmHg). Participants’ EDV (101.1 ± 15.8 ml to 104.2 ± 19.3 mL), ESV (38.7 ± 9.1 mL to 40.3 ± 11.6 mL), SpO2 (99.5 ± 0.79% to 99.5 ± 0.77%) and EF (61.9 ± 5.9% to 60.9 ± 6.4%) were only slightly changed (P > 0.05). However, cardiac output (4.3 ± 0.9 L/min to 5.4 ± 1.4 L/min) and cardiac index (3.7 ± 0.8 L/min per m2 to 4.5 ± 1.4 L/min per m2) increased significantly (P < 0.0001). We conclude that sympathetic stress induced by cold pressor test has marginal effect on ejection fraction and fractional shortening while increasing cardiac output and cardiac index in young healthy adults.
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Affiliation(s)
- Simiat O Elias
- Department of Physiology, Lagos State University College of Medicine, Ikeja, Lagos, Nigeria
| | - Reina E Ajayi
- Department of Physiology, Lagos State University College of Medicine, Ikeja, Lagos, Nigeria
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Gilotra NA, Wanamaker BL, Rahim H, Kunkel K, Yenokyan G, Schulman SP, Tedford RJ, Russell SD, Silber HA. Usefulness of Noninvasively Measured Pulse Amplitude Changes During the Valsalva Maneuver to Identify Hospitalized Heart Failure Patients at Risk of 30-Day Heart Failure Events (from the PRESSURE-HF Study). Am J Cardiol 2020; 125:916-923. [PMID: 31928720 DOI: 10.1016/j.amjcard.2019.12.027] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Accepted: 12/16/2019] [Indexed: 11/28/2022]
Abstract
The pulse amplitude ratio (PAR), the ratio of pulse pressure at the end of the Valsalva maneuver to before the onset, correlates with cardiac filling pressure. We have developed a handheld device that uses finger photoplethysmography to measure PAR and estimate left ventricular end diastolic pressure (LVEDP). Patients hospitalized with heart failure (HF) performed three 10-second trials of a standardized Valsalva maneuver (at 20 mm Hg measured via pressure transducer), while photoplethysmography waveforms were recorded, at admission and discharge. Combined primary outcome was 30-day HF hospitalization, intravenous diuresis, or death. Fifty-two subjects had discharge PAR testing; 12 met the primary outcome. Median PAR on admission was 0.55 (interquartile range: 0.40 to 0.70, n = 48) and on discharge was 0.50 (interquartile range: 0.36 to 0.69). Mean PAR-estimated LVEDP was significantly higher in subjects that had an event (20.2 vs 16.9 mm Hg, p = 0.043). Subjects with PAR-estimated LVEDP >19.5 mm Hg had an event rate hazard ratio of 4.57 (95% confidence interval 1.37, 15.19, p = 0.013) compared with patients with LVEDP 19.5 mm Hg or below, with significantly lower 30-day event-free survival (log-rank p = 0.006). In conclusion, noninvasively estimated LVEDP using the pulse amplitude response to a Valsalva maneuver in patients hospitalized for HF changes with diuresis and identifies patients at high risk for 30-day HF events. Detection of elevated filling pressures before hospital discharge may be useful in guiding HF management to reduce HF events.
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Affiliation(s)
- Nisha A Gilotra
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland.
| | - Brett L Wanamaker
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Hussein Rahim
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Katherine Kunkel
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Gayane Yenokyan
- Johns Hopkins Biostatistics Center, Johns Hopkins University School of Public Health, Baltimore, Maryland
| | - Steven P Schulman
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Ryan J Tedford
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina
| | - Stuart D Russell
- Division of Cardiology, Department of Medicine, Duke University School of Medicine, Durham, North Carolina
| | - Harry A Silber
- Division of Cardiology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
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7
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Cardiac Triangle Mapping: A New Systems Approach for Noninvasive Evaluation of Left Ventricular End Diastolic Pressure. FLUIDS 2019. [DOI: 10.3390/fluids4010016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Noninvasive and practical assessment of hemodynamics is a critical unmet need in the treatment of both chronic and acute cardiovascular diseases. Particularly, the ability to monitor left ventricular end-diastolic pressure (LVEDP) noninvasively offers enormous benefit for managing patients with chronic congestive heart failure. Recently, we provided proof of concept that a new cardiac metric, intrinsic frequency (IF), derived from mathematical analysis of non-invasively captured arterial waveforms, can be used to accurately compute cardiovascular hemodynamic measures, such as left ventricle ejection fraction (LVEF), by using a smartphone. In this manuscript, we propose a new systems-based method called cardiac triangle mapping (CTM) for hemodynamics evaluation of the left ventricle. This method is based on intrinsic frequency (IF) and systolic time interval (STI) methods that allows computation of LVEDP from noninvasive measurements. Since the CTM method only requires arterial waveform and electrocardiogram (ECG), it can eventually be adopted as a simple smartphone-based device, an inexpensive hand-held device, or perhaps (with future design modifications) a wearable sensor. Such devices, combined with this method, would allow for remote monitoring of heart failure patients.
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8
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Gilotra NA, Tedford RJ, Wittstein IS, Yenokyan G, Sharma K, Russell SD, Silber HA. Usefulness of Pulse Amplitude Changes During the Valsalva Maneuver Measured Using Finger Photoplethysmography to Identify Elevated Pulmonary Capillary Wedge Pressure in Patients With Heart Failure. Am J Cardiol 2017; 120:966-972. [PMID: 28754567 DOI: 10.1016/j.amjcard.2017.06.029] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Revised: 05/28/2017] [Accepted: 06/15/2017] [Indexed: 01/24/2023]
Abstract
The pulse amplitude ratio, the ratio of pulse pressure at the end of a Valsalva maneuver to before the onset of Valsalva, correlates with filling pressure. This study aimed to noninvasively estimate cardiac filling pressure in patients with heart failure. We developed a noninvasive handheld device to measure pulse amplitude ratio using finger photoplethysmography. In 69 patients who underwent right heart catheterization, photoplethysmography waveforms were recorded during a standardized Valsalva maneuver, and in 60 of these patients, pulse amplitude ratio was able to be calculated. Pulse amplitude ratio correlated with pulmonary capillary wedge pressure (PCWP) (r = 0.58, p <0.0001), particularly among those subjects with reduced ejection fraction (r = 0.60, p = 0.002, n = 25). A multivariable linear regression model for PCWP including pulse amplitude ratio, age, body mass index, systolic blood pressure, diastolic blood pressure, and heart rate yielded an R2 of 0.54. Difference in mean pulse amplitude ratio for subjects with a PCWP ≤15 mm Hg versus >15 mm Hg was statistically significant (p <0.0001, area under receiver operating characteristics curve 0.79 [0.66, 0.92]). Pulse amplitude ratio ≥0.55 predicted PCWP >15 mm Hg with 73% sensitivity and 77% specificity. Pulse amplitude ratio also increased by an average of 0.03 with a leg raise maneuver (p = 0.05, n = 36). In conclusion, we demonstrate that noninvasively measured response to the Valsalva maneuver in patients with HF can estimate PCWP and also detect changes within a single patient.
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9
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Shafi T, Mullangi S, Jaar BG, Silber H. Autonomic dysfunction as a mechanism of intradialytic blood pressure instability. Semin Dial 2017; 30:537-544. [PMID: 28730673 DOI: 10.1111/sdi.12635] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The autonomic nervous system (ANS) is the principal endogenous defense mechanism that maintains blood pressure in the setting of hypotension. Disruption of the ANS impairs this ability and can contribute to blood pressure instability, including hypotension and hypertension. In this narrative review, we provide an overview of the ANS and the consequences of its dysfunction in patients with end-stage kidney disease treated with dialysis. We also discuss possible mechanisms of this autonomic dysfunction that may need future investigation.
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Affiliation(s)
- Tariq Shafi
- Division of Nephrology, Department of Medicine, The Johns Hopkins University, Baltimore, MD, USA.,Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD, USA.,Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins University, Baltimore, MD, USA
| | - Surekha Mullangi
- Division of Nephrology, Department of Medicine, The Johns Hopkins University, Baltimore, MD, USA
| | - Bernard G Jaar
- Division of Nephrology, Department of Medicine, The Johns Hopkins University, Baltimore, MD, USA.,Welch Center for Prevention, Epidemiology and Clinical Research, Johns Hopkins University, Baltimore, MD, USA.,Nephrology Center of Maryland, Baltimore, MD, USA
| | - Harry Silber
- Division of Cardiology, Department of Medicine, The Johns Hopkins University, Baltimore, MD, USA
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Galiatsatos P, Win TT, Monti J, Johnston PV, Herzog W, Trost JC, Hwang CW, Fridman GY, Wang NY, Silber HA. Usefulness of a Noninvasive Device to Identify Elevated Left Ventricular Filling Pressure Using Finger Photoplethysmography During a Valsalva Maneuver. Am J Cardiol 2017; 119:1053-1060. [PMID: 28185634 DOI: 10.1016/j.amjcard.2016.11.063] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2016] [Revised: 11/30/2016] [Accepted: 11/30/2016] [Indexed: 11/25/2022]
Abstract
The high rate of re-hospitalization for heart failure might be reduced by improving noninvasive techniques for identifying elevated left ventricular (LV) filling pressure. We previously showed that changes in a finger photoplethysmography (PPG) waveform during the Valsalva maneuver (VM) reflect invasively measured LV end-diastolic pressure (LVEDP). We have since developed a hand-held device that analyzes PPG while guiding the expiratory effort of a VM. Here we assessed the sensitivity and specificity of this device for identifying elevated LVEDP in patients. We tested 82 participants (28 women), aged 40 to 85 years, before a clinically indicated left heart catheterization. Each performed a VM between 18 and 25 mm Hg for 10 seconds into a pressure transducer. PPG was recorded continuously before and during the VM. LVEDP was measured during the catheterization. An equation for calculating LVEDP was derived using (1) ratio of signal amplitudes: minimum during VM to average at baseline, (2) ratio of peak-to-peak time intervals: minimum during VM to average at baseline, and (3) mean blood pressure. Calculated and measured LVEDP were compared. The range of measured LVEDP was 4 to 35 mm Hg. Calculated LVEDP correlated with measured LVEDP (p <0.0001, r = 0.56). A calculated LVEDP >20 mm Hg had a 70% sensitivity and 86% specificity for identifying measured LVEDP >20 mm Hg (area under receiver-operating characteristic curve 0.83). In conclusion, a hand-held device for assessing LV filling pressure had high specificity and good sensitivity for identifying LVEDP >20 mm Hg, a clinically meaningful threshold in heart failure.
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Galiatsatos P, Parakh K, Monti J, Thavarajah S, Aneke-Ogbu H, Watson A, Kim D, Wang NY, Shafi T, Silber HA. A finger photoplethysmography waveform during the valsalva maneuver detects changes in left heart filling pressure after hemodialysis. BMC Nephrol 2015; 16:138. [PMID: 26272208 PMCID: PMC4536782 DOI: 10.1186/s12882-015-0135-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 07/30/2015] [Indexed: 01/05/2023] Open
Abstract
Background A noninvasive system for determining left ventricular (LV) filling pressure may help to improve personalized fluid removal goals in hemodialysis patients. We previously showed that the change in photoplethysmography (PPG) pulse amplitude measured by finger PPG during a Valsalva maneuver correlates with invasively measured left ventricular end-diastolic pressure (LVEDP). This key PPG change, the ratio of finger PPG pulse amplitude at end-Valsalva to baseline, is known as the Pulse Amplitude Ratio, PAR. The objective of this study was to determine how PAR changes after fluid removal in hemodialysis. Methods We tested subjects with end-stage renal disease, before and after hemodialysis. Each subject performed a Valsalva maneuver with an effort of 20 mmHg for 10 s, guided by the device display. Finger PPG was recorded continuously before and during the maneuver. PAR was calculated automatically. Results Twenty-seven subjects (21 Males) ages 25–75 years were tested. Access sites were AV-fistulas of the arm predominantly. Weight decreased from 99.7 ± 36.9 kg to 97.0 ± 36.0 kg (p < 0.0003) with an average fluid removal of 3.07 ± 1.08 l. Correspondingly, PAR decreased from 0.74 ± 0.24 to 0.62 ± 0.23 (p = 0.003). The change in PAR was correlated with baseline PAR (r = 0.48, p = 0.01). Conclusion An index of left heart filling pressure obtained noninvasively using finger photoplethysmography during the Valsalva maneuver is sensitive enough to detect reductions in filling pressure after fluid removal with hemodialysis. Further studies are warranted to determine if this method can be used to guide fluid removal during hemodialysis.
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Affiliation(s)
- Panagis Galiatsatos
- Department of Medicine, Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, 4940 Eastern Avenue, Baltimore, MD, 21224, USA.
| | - Kapil Parakh
- Division of Cardiology, Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, 4940 Eastern Avenue, Baltimore, MD, 21224, USA.
| | - Jennifer Monti
- Department of Medicine, Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, 4940 Eastern Avenue, Baltimore, MD, 21224, USA.
| | - Sumeska Thavarajah
- Division of Nephrology, Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, 4940 Eastern Avenue, Baltimore, MD, 21224, USA.
| | - Harriet Aneke-Ogbu
- Division of Cardiology, Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, 4940 Eastern Avenue, Baltimore, MD, 21224, USA.
| | - Amaris Watson
- Division of Cardiology, Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, 4940 Eastern Avenue, Baltimore, MD, 21224, USA.
| | - Daniel Kim
- Department of Medicine, Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, 4940 Eastern Avenue, Baltimore, MD, 21224, USA.
| | - Nae-Yuh Wang
- Department of Medicine, Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, 4940 Eastern Avenue, Baltimore, MD, 21224, USA.
| | - Tariq Shafi
- Division of Nephrology, Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, 4940 Eastern Avenue, Baltimore, MD, 21224, USA.
| | - Harry A Silber
- Division of Cardiology, Johns Hopkins University School of Medicine, Johns Hopkins Bayview Medical Center, 4940 Eastern Avenue, Baltimore, MD, 21224, USA.
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Lagro J, Schoon Y, Heerts I, Meel-van den Abeelen ASS, Schalk B, Wieling W, Olde Rikkert MGM, Claassen JAHR. Impaired systolic blood pressure recovery directly after standing predicts mortality in older falls clinic patients. J Gerontol A Biol Sci Med Sci 2013; 69:471-8. [PMID: 23873962 DOI: 10.1093/gerona/glt111] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
BACKGROUND Normally, standing up causes a blood pressure (BP) drop within 15 seconds, followed by recovery to baseline driven by BP control mechanisms. The prognostic value of this initial BP drop, but also of the recovery hereafter, is unknown. The aim of this study was to examine the prognostic value of these BP characteristics in response to standing. METHODS In a retrospective cohort study of 238 consecutive patients visiting our falls outpatient clinic, we examined the relation between all-cause mortality and BP decline and recovery directly after active standing up with Cox proportional hazards analyses. RESULTS Of 238 patients (mean age 78.4 ± 7.8 years), during a median follow-up of 21.0 months, 36 (15%) patients died. Neither absolute nor relative (%) initial BP drop after standing predicted mortality. In contrast, the magnitude of BP recovery 40-60 seconds after standing was associated with mortality, even after adjustment for age, comorbidity, and other baseline characteristics. When systolic BP had recovered to less than 80% of prestanding baseline after 60 seconds of standing, this was a powerful independent predictor of mortality (hazard ratio: 3.00; 95% confidence interval 1.17-7.68). CONCLUSIONS Failure to recover from BP decline in the first minute after active standing up is associated with excess mortality in falls clinic patients. A recovery of systolic BP to less than 80% of baseline after 60 seconds may be used as an easily available cardiovascular marker for increased mortality risk in older falls clinic patients.
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Affiliation(s)
- Joep Lagro
- Department of Geriatric Medicine, Radboud University Nijmegen Medical Centre, University mail code 925, PO Box 9100, 6500 HB Nijmegen, The Netherlands.
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Stanley WC, Keehan KH. Update on innovative initiatives for the American Journal of Physiology-Heart and Circulatory Physiology. Am J Physiol Heart Circ Physiol 2013; 304:H1045-9. [PMID: 23457015 DOI: 10.1152/ajpheart.00082.2013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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14
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Wang Z, Yuan LJ, Cao TS, Yang Y, Duan YY, Xing CY. Simultaneous beat-by-beat investigation of the effects of the Valsalva maneuver on left and right ventricular filling and the possible mechanism. PLoS One 2013; 8:e53917. [PMID: 23342040 PMCID: PMC3544743 DOI: 10.1371/journal.pone.0053917] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2012] [Accepted: 12/04/2012] [Indexed: 12/03/2022] Open
Abstract
Although the influence of the Valsalva maneuver on the heart and circulatory system has been investigated, the mechanism of intrathoracic pressure influencing cardiovascular function is unclear. To test our hypothesis that the interaction between the anatomy-determined partially-intrathoracic system and the fully-intrathoracic system might explain those issues and help to disclose the mechanism, we used the Hitachi dual pulse wave Doppler echocardiographic apparatus to investigate simultaneously the beat-by-beat influence of 40-mmHg Valsalva maneuver on left and right cardiac ventricular filling in 30 male adult volunteers. The mitral and tricuspid blood inflow velocity spectra during the Valsalva maneuver were recorded simultaneously. The peak velocity (PV), velocity–time integral (VTI) and inflow volume (IV) of each cycle were measured or calculated. The PV, VTI and IV of the left heart remained unchanged at the first beat after the Valsalva maneuver onset (compared with those at rest, p>0.1) and then decreased gradually to the lowest at the 11±1.2th beat (range, 9th to 12th beat). Simultaneously, the PV, VTI and IV of the right heart decreased significantly (p<0.05) at the first cycle, decreased rapidly to the lowest at the 6±0.8th beat (range, 4th to 7th beat) and then increased gradually to the 9±1.3th beat (range, 8th to 10th beat). These results suggest that the left heart and right heart have different physiological responses to the Valsalva maneuver. These could be explained by our hypothesis, the interaction between the partially-intrathoracic system and the fully-intrathoracic system, which might help to disclose the mechanism of how intrathoracic pressure influences the heart and circulatory system.
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Affiliation(s)
- Zhen Wang
- Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi’an, China
| | - Li-jun Yuan
- Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi’an, China
| | - Tie-sheng Cao
- Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi’an, China
- * E-mail:
| | - Yong Yang
- Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi’an, China
| | - Yun-you Duan
- Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi’an, China
| | - Chang-yang Xing
- Department of Ultrasound Diagnostics, Tangdu Hospital, Fourth Military Medical University, Xi’an, China
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15
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Shoaib A, Mabote T, Zuhair M, Kassianides X, Cleland JGF. Acute heart failure (suspected or confirmed): Initial diagnosis and subsequent evaluation with traditional and novel technologies. ACTA ACUST UNITED AC 2013. [DOI: 10.4236/wjcd.2013.33046] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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