The Valsalva maneuver-3 centuries later

Preeclamptic heart failure - perioperative concerns and management: a narrative review

Preeclampsia is an important cause of heart failure during pregnancy and the postpartum period. The aim of this review is to elucidate the pathophysiology and clinical features of preeclamptic heart failure and describe the medical and anesthetic management of these high-risk parturients. This article reviews the current evidence base regarding preeclamptic heart failure and its pathophysiology, types, and clinical features. We also describe the medical and anesthetic management of these patients during the peripartum period. Heart failure due to preeclampsia can present as either systolic or diastolic dysfunction. The management strategies of systolic heart failure include dietary salt restriction, diuresis, and cautious use of beta-blockers and vasodilators. Diuretics are the mainstay in the treatment of diastolic heart failure. In the absence of obstetric indications, vaginal delivery is the safest mode of delivery in these high-risk patients, and the use of an early labor epidural for analgesia is recommended. These patients would require increased invasive monitoring during labor and vaginal delivery. Neuraxial and general anesthesia have been used successfully for cesarean section in these patients but require crucial modifications of the standard technique. Uterotonic drugs have significant cardiovascular and pulmonary effects, and a clear understanding of these is essential during the management of these patients. Preeclamptics with heart failure require individualized peripartum care, as cardiac decompensation is an important risk factor for maternal and neonatal morbidity and mortality. These high-risk parturients benefit from timely multidisciplinary team inputs and collaborated management.

Effects of high-gravity acceleration forces and anti-gravity maneuver on the cardiac function of fighter pilots

The fighter pilots exposed to high gravitational (G) acceleration must perform anti-G maneuvers similar to the Valsalva maneuver. However, the effects of high-G acceleration and anti-G maneuvers on cardiac function have rarely been studied. This study aimed to investigate the effects of high-G forces on cardiac function of fighter pilots. Fighter pilots who underwent regular health check-ups and echocardiography were included (n = 29; 100% men, 41 ± 10 years old; mean flight time, 1821 ± 1186 h). Trainees who had not experienced any flights were included in the control group (n = 16; 100% men, 36 ± 17 years old). Echocardiographic data included left ventricular chamber size, systolic and diastolic functions, right ventricular systolic pressure (RVSP), inferior vena cava (IVC) collapsibility, and tricuspid annular plane systolic excursion (TAPSE). No significant differences in left ventricular ejection fraction, RVSP, or IVC collapsibility were observed between two groups. In the multivariate linear regression analysis with total flight time as an independent continuous variable for fighter pilots, TAPSE was positively correlated with total flight time. The experience of fighter pilots who were exposed to high-G acceleration forces and anti-G maneuvers did not cause cardiac structural changes, but the exposure might be associated with right heart function changes.

Care for the Obstetric Patient with Complex Cardiac Disease

The prevalence of cardiac disease-related maternal morbidity and mortality is on the rise in the United States. To ensure safe management of pregnancy in patients with cardiovascular disease, pre-delivery evaluation by a multidisciplinary Pregnancy Heart Team should occur. Appropriate anesthetic, cardiac, and obstetric care are essential. Risk stratification tools evaluate the etiology and severity of cardiovascular disease to determine the appropriate hospital type and location for delivery and anesthetic management. Intrapartum hemodynamic monitoring may need to be intensified, and neuraxial analgesia and anesthesia are generally appropriate. The anesthesiologist must be prepared for obstetric and cardiac emergencies.

Standard volume infusion unmasked diastolic dysfunction in pediatric heart transplant recipients during surveillance cardiac catheterization, but without echocardiographic correlates

BACKGROUND

Adult experience evaluating left ventricular diastolic function (LVDFx) includes volume administration during catheterization while obtaining pulmonary capillary wedge pressures (PCWP) or left ventricular end diastolic pressures (LVEDP). Catheterization is inherently challenging in pediatric patients, making echocardiographic assessment ideal. Pediatric echocardiographic studies predicting LVDFx have variable hemodynamic and hydration conditions and have produced inconsistent results. We evaluated the association between simultaneous echocardiographic and catheterization assessment of LVDFx, using a fluid bolus for optimal loading conditions.

METHODS

Prospective cohort study of pediatric heart transplant recipients receiving echocardiogram simultaneous with routine cardiac catheterization. Mitral valve inflow velocities, septal and lateral wall tissue Doppler indices, and PCWP and/or LVEDP were obtained and repeated following a 10 ml/kg bolus. Echocardiographic parameters were evaluated for an association with changes in PCWP or LVEDP following the bolus. Abnormal LVDFx was defined as PCWP or LVEDP ≥12 mm Hg.

RESULTS

Twenty-nine patients underwent catheterization. Median pre-bolus PCWP and LVEDP were 11.0 mm Hg and 10.0 mm Hg, respectively. After bolus, median PCWP and LVEDP increased to 14.0 mm Hg (p < .001) and 13 mm Hg (p < .001), respectively. Of 21 patients with normal pre-bolus catheterization hemodynamics, 14 (66.7%) increased to abnormal following fluid bolus. Using area under an ROC, no echocardiographic parameter of LVDFx, or their ratios, were associated with predetermined abnormal LVEDP and/or PCWP.

CONCLUSION

After bolus, our cohort demonstrated significant increases in LVEDP and/or PCWP, unmasking diastolic dysfunction. Fluid challenges should be considered in pediatric patients undergoing cardiac catheterization with suspected diastolic dysfunction. Echocardiographic measurements were unable to discriminate between normal and abnormal LVEDP and/or PCWP.

Cardiovascular Responses to Commonly Used Tests in and Outside of the Laboratory Settings

Several tests are available for assessing cardiovascular response to various interventions which may be given in the laboratory, or outside of it in the field. The tests are meant to excite or deactivate cardiovascular and other sensory receptors which signal the central mechanisms. They have been found useful in generating data to study cardiovascular effects on subjects exposed to specialized physical training (e.g., athletes), in the evaluation of people engaged in special occupations such as pilots, astronauts, and other military personnel, and in training undergraduate and postgraduate students. If the response does not fit into the physiological norm, it may reflect a temporary aberration, or a more serious defect in the cardiovascular control mechanism because of disease. Interpretation of data generated may vary between various operators/observers. Here, an attempt has been made to bring out responses of the cardiovascular system to the commonly used tests, and their applicability in clinical situations.

Physiology of Continuous-Flow Left Ventricular Assist Device Therapy

The expanding use of continuous-flow left ventricular assist devices (CF-LVADs) for end-stage heart failure warrants familiarity with the physiologic interaction of the device with the native circulation. Contemporary devices utilize predominantly centrifugal flow and, to a lesser extent, axial flow rotors that vary with respect to their intrinsic flow characteristics. Flow can be manipulated with adjustments to preload and afterload as in the native heart, and ascertainment of the predicted effects is provided by differential pressure-flow (H-Q) curves or loops. Valvular heart disease, especially aortic regurgitation, may significantly affect adequacy of mechanical support. In contrast, atrioventricular and ventriculoventricular timing is of less certain significance. Although beneficial effects of device therapy are typically seen due to enhanced distal perfusion, unloading of the left ventricle and atrium, and amelioration of secondary pulmonary hypertension, negative effects of CF-LVAD therapy on right ventricular filling and function, through right-sided loading and septal interaction, can make optimization challenging. Additionally, a lack of pulsatile energy provided by CF-LVAD therapy has physiologic consequences for end-organ function and may be responsible for a series of adverse effects. Rheological effects of intravascular pumps, especially shear stress exposure, result in platelet activation and hemolysis, which may result in both thrombotic and hemorrhagic consequences. Development of novel solutions for untoward device-circulatory interactions will facilitate hemodynamic support while mitigating adverse events. © 2021 American Physiological Society. Compr Physiol 12:1-37, 2021.

Obstetric Anesthesia and Heart Disease: Practical Clinical Considerations

Maternal morbidity and mortality as a result of cardiac disease is increasing in the United States. Safe management of pregnancy in women with heart disease requires appropriate anesthetic, cardiac, and obstetric care. The anesthesiologist should risk stratify pregnant patients based upon cardiac disease etiology and severity in order to determine the appropriate type of hospital and location within the hospital for delivery and anesthetic management. Increased intrapartum hemodynamic monitoring may be necessary and neuraxial analgesia and anesthesia is typically appropriate. The anesthesiologist should anticipate obstetric and cardiac emergencies such as emergency cesarean delivery, postpartum hemorrhage, and peripartum arrhythmias. This clinical review answers practical questions for the obstetric anesthesiologist and the nonsubspecialist anesthesiologist who regularly practices obstetric anesthesiology.

Modified Method of Contrast Transthoracic Echocardiography for the Diagnosis of Patent Foramen Ovale

Purpose

To compare the sensitivity and specificity of modified and traditional methods of contrast echocardiography of the right portion of the heart in patients with a suspicion of patent foramen ovale (PFO).

Methods

The study population consisted of 506 patients with high clinical suspicion of PFO. The traditional Valsalva maneuver consists of expiration against a closed glottis after a full inspiration. A modified Valsalva maneuver was performed with a handmade pressure monitoring device, which measured pressure during performance of the Valsalva maneuver. Modified and traditional methods of contrast echocardiography were performed among all patients. Contrast transesophageal echocardiography (TEE) was regarded as the gold standard.

Results

A total of 279 patients with PFO were confirmed by TEE. 259 cases (sensitivity: 92.83%) were detected by a modified method of contrast echocardiography of the right portion of the heart, while 234 cases were detected using the traditional method (sensitivity: 83.87%). The sensitivity of modified contrast echocardiography of the right portion of the heart was significantly higher than that of the traditional method (92.83% vs. 83.87%, P=0.001). However, there was no significant difference in the specificity of the two methods for the diagnosis of PFO (97.35% vs. 96.03%, P=0.431). Additionally, the results of semiquantitative evaluation of PFO using modified method failed to show a more positive rate than shown by the traditional method (Z=−1.782, P=0.075).

Conclusions

Modified contrast echocardiography of the right portion of the heart yielded a higher sensitivity than the traditional method, which contributed to the diagnosis of cardiac PFO. The research was a part of a register study (https://register.clinicaltrials.gov/ ClinicalTrials ID: NCT02777359).

Provocative maneuvers to improve patent foramen ovale detection: A brief review of the literature

Patent foramen ovale (PFO) is the most common type of inter-atrial shunt, with prevalence as high as 30%. Detection of PFO has implications in patients with stroke, peripheral embolism, decompression illness, and other conditions. Transesophageal echo (TEE) with saline contrast injection is the current standard for PFO detection, but even with TEE, PFOs are sometimes missed. With advances in percutaneous PFO closure therapies and proven long-term benefit of closure, accurate PFO detection takes on cardinal importance. Various provocative maneuvers to enhance PFO detection are in clinical use and have been studied. The Valsalva maneuver has long-held position as the ideal provocation to unmask PFO, but other maneuvers such as cough, sniff, Müller's, and more have gained relevance. In this article, we will examine various maneuvers and discuss their utility in PFO detection.

Intraoperative Valsalva maneuver: a narrative review

The Valsalva maneuver (VM) involves expiratory effort against a closed mouth and/or glottis in the sitting or supine position with the increased intraoral and intrathoracic pressure raised to 40 mmHg for 15-20 sec after which the pressure is suddenly released and the breathing restored to normal. Complex cardiovascular and other physiologic changes occur during the VM. The VM has been used for diagnostic and therapeutic reasons as well as intraoperatively during specific surgical procedures. Although the VM is usually safe, rare complications have been reported. This review examines the published literature surrounding the VM and explores the physiologic changes that occur during its performance. Attempts have been made to understand its intraoperative uses and complications and how these can be prevented.

Imaging Assessment of the Interatrial Septum for Transcatheter Atrial Septal Defect and Patent Foramen Ovale Closure

Transcatheter closure of atrial septal defects and patent foramen ovale has become increasingly common with advances in device and imaging technology. The percutaneous approach is now the preferred method of closure when anatomically suitable. Two-dimensional and 3-dimensional echocardiography determines anatomic suitability by characterizing the interatrial defect and its surrounding structures, and is critical for intraprocedural guidance and postprocedure follow-up. This article provides an overview of interatrial anatomy as it pertains to interventional considerations and discusses the transthoracic, transesophageal, and intracardiac echocardiographic modalities used for periprocedural and intraprocedural imaging of the interatrial septum.

Valsalva maneuver exacerbates left atrial compression in patients with large hiatal hernia

INTRODUCTION

Hiatal hernia (HH) can cause left atrial (LA) compression and impair LA filling. We evaluated the cardiac effects of preload reduction and abdominal strain induced by Valsalva maneuver (VM) in large HH patients.

METHODS

LA and left ventricular (LV) dimensions were measured using 2D transthoracic echocardiography at rest and during VM in HH patients (n=55, 70±10 years) and controls (n=22, 67±6 years). Biplane LV volumes (n=39) and mitral inflow pulse-wave Doppler parameters (n=27) were also evaluated. In HH patients, resting LA compression was graded qualitatively (none-mild or moderate-severe).

RESULTS

In both controls and HH patients, VM significantly decreased LA (controls, 19±2 vs 16±3 mm/m² ; HH, 16±5 vs 9±5 mm/m² ) and LV diameters (22±3 vs 19±3 mm/m² ; 21±3 vs 17±3 mm/m² ) and LV volume (38±8 vs 26±10 mL/m² ; 31±8 vs 19±9 mL/m² ) (P<.001 for all). VM decreased LA diameter significantly more in HH patients than controls (-42% vs -16%, P<.001). HH patients with none-mild resting LA compression exhibited significantly greater LA diameter reduction than controls (-38±23% vs -16±13% P=.0003) despite similar resting LA diameters. LV volumes were similarly decreased by VM in HH patients and controls irrespective of resting LA compression severity indicating relative preservation of LV filling. LA diameter correlated inversely with early diastolic filling velocity during VM in HH patients (R=-.43, P=.03) but not controls (R=.18, P=.43).

CONCLUSION

VM can markedly exacerbate LA compression in HH patients; however, LV filling is relatively less affected possibly due to augmented early diastolic filling. Conditions associated with decreased preload and increased intra-abdominal pressure may exacerbate the cardiac effects of large HH.

Modeling Pathological Hemodynamic Responses to the Valsalva Maneuver

The Valsalva maneuver (VM) consisting in a forced expiration against closed airways is one of the most popular clinical tests of the autonomic nervous system function. When properly performed by a healthy subject, it features four characteristic phases of arterial blood pressure (BP) and heart rate (HR) variations, based on the magnitude of which the autonomic function may be assessed qualitatively and quantitatively. In patients with some disorders or in healthy patients subject to specific conditions, the pattern of BP and HR changes during the execution of the Valsalva maneuver may, however, differ from the typical sinusoidal-like pattern. Several types of such abnormal responses are well known and correspond to specific physiological conditions. In this paper, we use our earlier mathematical model of the cardiovascular response to the Valsalva maneuver to show that such pathological responses may be simulated by changing individual model parameters with a clear physiological meaning. The simulation results confirm the adaptability of our model and its usefulness for diagnostic or educational purposes.

Influence of the Valsalva maneuver on cardiac hemodynamics and right to left shunt in patients with patent foramen ovale

The purpose of this study was to investigate the influence of the Valsalva maneuver (VM) on cardiac hemodynamics in patients with patent foramen ovale (PFO). Sixty-five patients who were highly suspected to have PFO were included. The changes in E, A, E/A ratio of mitral valve blood flow, E, A, E/A ratio of tricuspid valve blood flow, left ventricular end-diastolic volume, area and right atrial area during the resting state and the strain phase of the Valsalva maneuver were observed by transthoracic echocardiography (TTE). Statistical analyses were performed using SPSS Version18.0. Compared to the resting state, mitral valve diastolic velocity E and A peaks at the strain phase of the Valsalva maneuver significantly decreased (P < 0.05), left ventricular end diastolic volume(LVEDV) and area(LVEDA) decreased significantly (P < 0.05), while E/A ratio of mitral valve, tricuspid valve systolic velocity E and A peaks and E/A ratio remained unchanged (P > 0.05). PFO hemodynamic changes mainly occurred in the left ventricle when the Valsalva maneuver was performed. The Valsalva maneuver increased pressure in the chest, then pulmonary venous return was impeded, which resulted in left ventricular limited filling, and E and A peaks decreased. The pressure of the left ventricle and atrium was lower than that of the right side, which resulted in right-to-left shunt (RLS) through PFO.

The Valsalva manoeuvre: physiology and clinical examples

The Valsalva manoeuvre (VM), a forced expiratory effort against a closed airway, has a wide range of applications in several medical disciplines, including diagnosing heart problems or autonomic nervous system deficiencies. The changes of the intrathoracic and intra-abdominal pressure associated with the manoeuvre result in a complex cardiovascular response with a concomitant action of several regulatory mechanisms. As the main aim of the reflex mechanisms is to control the arterial blood pressure (BP), their action is based primarily on signals from baroreceptors, although they also reflect the activity of pulmonary stretch receptors and, to a lower degree, chemoreceptors, with different mechanisms acting either in synergism or in antagonism depending on the phase of the manoeuvre. A variety of abnormal responses to the VM can be seen in patients with different conditions. Based on the arterial BP and heart rate changes during and after the manoeuvre several dysfunctions can be hence diagnosed or confirmed. The nature of the cardiovascular response to the manoeuvre depends, however, not only on the shape of the cardiovascular system and the autonomic function of the given patient, but also on a number of technical factors related to the execution of the manoeuvre including the duration and level of strain, the body position or breathing pattern. This review of the literature provides a comprehensive analysis of the physiology and pathophysiology of the VM and an overview of its applications. A number of clinical examples of normal and abnormal haemodynamic response to the manoeuvre have been also provided.

BIOMECHANICS OF POSITIVE INTRATHORACIC PRESSURE AND ITS EFFECTS ON LEFT VENTRICULAR FILLING IN HEALTHY SUBJECTS

This study aims to explore the biomechanics of positive intrathoracic pressure and its effects on left ventricle (LV) filling in healthy subjects. 30 healthy subjects were enlisted to perform a Valsalva maneuver (VM) with a load of 40[Formula: see text]mmHg lasted 10[Formula: see text]s. LV filling parameters were measured by echocardiography at rest and at 10[Formula: see text]s during the VM. Compared with the at rest values, LV early inflow velocity (E) decreased significantly ([Formula: see text]), late inflow velocity (A) decreased insignificantly ([Formula: see text]), while the E/A ratio decreased significantly ([Formula: see text]) after 10[Formula: see text]s of the strain phase of the VM. LV septal early tissue velocity ([Formula: see text]) and lateral early tissue velocity ([Formula: see text]) of the mitral did not change ([Formula: see text]), while the [Formula: see text] ratio and the [Formula: see text] ratio decreased significantly ([Formula: see text] after 10[Formula: see text]s during the VM. Based on these results, biomechanical analysis suggests that the effects of positive intrathoracic pressure on the LV free wall impede LV diastolic motion, which may be one of the factors contributing to a decrease in E and the E/A ratio. Positive intrathoracic pressure also increases the flow resistance of the LV and pulmonary vasculature, which may contribute to a decrease in E, the [Formula: see text] ratio, and the [Formula: see text] ratio.

A Comparison of Transthroracic Echocardiograpy and Transcranial Doppler With Contrast Agent for Detection of Patent Foramen Ovale With or Without the Valsalva Maneuver

Patent foramen ovale (PFO) is a remnant of the fetal circulation exist in 20% of the general population. The purpose of our study was to compare of transthoracic echocardiography (TTE) and contrast-transcranial Doppler sonography (c-TCD) in the diagnosis and quantification of PFO with or without the Valsalva maneuver (VM).We studied 106 patients with a high clinical suspicion for PFO prospectively. Simultaneous c-TCD and TTE were conducted using agitated saline solution to detect right to left shunt (RLS). To classify RLS, mainly PFO, we applied a 4-level visual classification for c-TCD test: no occurrence of micro-embolic signals; grade I, 1 to 10 signals; grade II, 10 to 30 signals but not curtain; and grade III, curtain pattern. We used the number of micro-bubbles appeared in left atrium per frame image to define classification for TTE test: no occurrence of micro-bubbles; grade I, 1 to 10 micro-bubbles; grade II, 10 to 30 micro-bubbles; and grade III, more than 30 micro-bubbles or left atrium nearly filled with micro-bubbles or left atrial opacity. Statistical analyses were performed using SPSS Version 18.0.RLS was detected in 36.0% in c-TCD test and in 46% in TTE test at rest (P = 0.158). And during the VM, RLS was detected in 99.0% in c-TCD test and in 83.0% in TTE test (P < 0.001). Compared with the positive results of c-TCD and TTE at rest, the positive results of them with VM is more higher, respectively (all P < 0.001). The VM obviously increased the number of micro-bubbles shunting.Both c-TCD and TTE should used as initial screening tool for PFO. VM increases the size of shunt. VM resulted in detection of more RLS both in c-TCD and TTE tests.

Importance of an adequately performed Valsalva maneuver for detecting a right-to-left shunt indicating foramen ovale reopening

OBJECTIVES

The purpose of this study was to investigate the importance of an adequately performed Valsalva maneuver for detecting a right-to-left shunt indicating reopening of the functional closure of the foramen ovale.

METHODS

We prospectively analyzed 260 patients (102 women and 158 men; mean age ± SD, 41 ± 19 years; range, 13-83 years) who underwent transesophageal echocardiography and agitated saline injection. Two-dimensional echocardiography, color Doppler imaging, and microbubbles were used to detect right-to-left shunts, and the Valsalva maneuver was performed to determine whether the functional closure of the foramen ovale had reopened.

RESULTS

Transesophageal echocardiography with color Doppler imaging identified a patent foramen ovale in 20 patients: 18 patients with a patent foramen ovale had left-to-right shunts, and 2 patients with atrial septal defects had bidirectional shunts. Both patients with atrial septal defects showed right-to-left shunt microbubbles without and with the Valsalva maneuver, whereas all 18 patients with a patent foramen ovale showed right-to-left shunt microbubbles only after the Valsalva maneuver. Foramen ovale reopening was identified by transesophageal echocardiography in an additional 40 patients with no shunt during rest on agitated saline injection and in whom the right-to-left shunt appeared only after the Valsalva maneuver. The Valsalva maneuver could cause an atrial septal swing, and its sensitivity and specificity were 100%.

CONCLUSIONS

An adequately performed Valsalva maneuver is important for detecting a right-to-left shunt indicating reopening of the functional closure of the foramen ovale.

The role of hemodynamic catheterization in the evaluation of hypertrophic obstructive cardiomyopathy: A case series

Confirmation of the presence and magnitude of left ventricular outflow tract (LVOT) obstruction is a critical component of the evaluation of symptoms in patients with hypertrophic cardiomyopathy (HCM). The presence of LVOT obstruction in patients with severe symptoms refractory to pharmacologic therapy identifies a subgroup of HCM patients who may benefit from septal reduction therapy. Two-dimensional echocardiography with continuous wave Doppler is the main tool for confirming the presence and severity of LVOT obstruction in HCM. However, when uncertainty remains following non-invasive evaluation, invasive hemodynamics studies are required to confirm and quantify LVOT obstruction. In this manuscript we describe a series of 6 cases in which hemodynamic catheterization is instrumental in supplementing non-invasive imaging in the assessment of LVOT obstruction in HCM.

Real-time phase-contrast flow MRI of the ascending aorta and superior vena cava as a function of intrathoracic pressure (Valsalva manoeuvre)

OBJECTIVE

Real-time phase-contrast flow MRI at high spatiotemporal resolution was applied to simultaneously evaluate haemodynamic functions in the ascending aorta (AA) and superior vena cava (SVC) during elevated intrathoracic pressure (Valsalva manoeuvre).

METHODS

Real-time phase-contrast flow MRI at 3 T was based on highly undersampled radial gradient-echo acquisitions and phase-sensitive image reconstructions by regularized non-linear inversion. Dynamic alterations of flow parameters were obtained for 19 subjects at 40-ms temporal resolution, 1.33-mm in-plane resolution and 6-mm section thickness. Real-time measurements were performed during normal breathing (10 s), increased intrathoracic pressure (10 s) and recovery (20 s).

RESULTS

Real-time measurements were technically successful in all volunteers. During the Valsalva manoeuvre (late strain) and relative to values during normal breathing, the mean peak flow velocity and flow volume decreased significantly in both vessels (p < 0.001) followed by a return to normal parameters within the first 10 s of recovery in the AA. By contrast, flow in the SVC presented with a brief (1-2 heartbeats) but strong overshoot of both the peak velocity and blood volume immediately after pressure release followed by rapid normalization.

CONCLUSION

Real-time phase-contrast flow MRI may assess cardiac haemodynamics non-invasively, in multiple vessels, across the entire luminal area and at high temporal and spatial resolution.

ADVANCES IN KNOWLEDGE

Future clinical applications of this technique promise new insights into haemodynamic alterations associated with pre-clinical congestive heart failure or diastolic dysfunction, especially in cases where echocardiography is technically compromised.

Eponyms in cardiopulmonary reflexes

Heart rate, blood pressure, and vascular tone, as well as ventilator drive, respiratory rate, and breathing pattern, are, at least in part, under the control of specific reflexes. These reflexes are mediated by a complex network of baroreceptors and chemoreceptors in the arterial system of the carotids, aorta, and left heart, including receptors in the left atrium, the ventricle, and the coronary arteries; irritants in the upper airways and stretch receptors in the lower airways; juxtacapillary-located nonmyelinated fibers in the alveoli and in the bronchial arterial system; and muscle spindles that evoke changes in the membrane potential upon alteration of sarcolemmal tension. Some of these reflexes, usually named after the first individual to describe them, have spread as eponyms into propaedeutic education and clinical work. Because these euphonic eponyms are enigmatic to most clinicians today, this article is intended to provide a short overview of these reflexes, including the historical context of their describers. As evidenced by their clinical implications, the eponyms discussed are revealed to be more than curiosities taught during undergraduate medical education.

Failure to Unmask Pseudonormal Diastolic Function by a Valsalva Maneuver

Background—

For the clinical assessment of patients with dyspnea, the inversion of the early (E) and late (A) transmitral flow during Valsalva maneuver (VM) frequently helps to distinguish pseudonormal from normal filling pattern. However, in an important number of patients, VM fails to reveal the change from dominant early mitral flow velocity toward larger late velocity.

Methods and Results—

From December 2009 to October 2010, we selected consecutive patients with abnormal filling with (n=25) and without E/A inversion (n=25) during VM. Transmitral, tricuspid, and pulmonary Doppler traces were recorded and the degree of insufficiency was estimated. After evaluating all standard echocardiographic morphological, functional, and flow-related parameters, it became evident that the failure to unmask the pseudonormal filling pattern by VM was related to the degree of the tricuspid insufficiency (TI). TI was graded as mild in 24 of 25 patients in the group with E/A inversion during VM, whereas TI was graded as moderate to severe in 24 of the 25 patients with pseudonormal diastolic function without E/A inversion during VM.

Conclusions—

Our data suggest that TI is a major factor to prevent E/A inversion during a VM in patients with pseudonormal diastolic function. This probably is due to a decrease in TI resulting in an increase in forward flow rather than the expected decrease during the VM. Thus, whenever a pseudonormal diastolic filling pattern is suspected, the use of a VM is not an informative discriminator in the presence of moderate or severe TI.

Perioperative assessment of diastolic dysfunction

Assessment of diastolic function should be a component of a comprehensive perioperative transesophageal echocardiographic examination. Abnormal diastolic function exists in >50% of patients presenting for cardiac and high-risk noncardiac surgery, and has been shown to be an independent predictor of adverse postoperative outcome. Normalcy of systolic function in 50% of patients with congestive heart failure implicates diastolic dysfunction as the probable etiology. Comprehensive evaluation of diastolic function requires the use of various, load-dependent Doppler techniques This is further complicated by the additional effects of dehydration and anesthetic drugs on myocardial relaxation and compliance as assessed by these Doppler measures. The availability of more sophisticated Doppler techniques, e.g., Doppler tissue imaging and flow propagation velocity, makes it possible to interrogate left ventricular diastolic function with greater precision, analyze specific stages of diastole, and to differentiate abnormalities of relaxation from compliance. Additionally, various Doppler-derived ratios can be used to estimate left ventricular filling pressures. The varying hemodynamic environment of the operating room mandates modification of the diagnostic algorithms used for ambulatory cardiac patients when left ventricular diastolic function is evaluated with transesophageal echocardiography in anesthetized surgical patients.

Valsalva maneuver, Müller maneuver: hemodynamic and reflex mechanisms, relevances

A Valsalva- és Müller-manőverek az idő próbáját kiállva, ma is gyakran alkalmazott, egyszerű és népszerű vizsgálóeszközök az orvosi gyakorlatban. A manőverek közönséges élethelyzetek és egyes kórállapotok modellezésére egyaránt alkalmasak. A Valsalva-manővert leginkább neuropathiás betegek autonóm reflex tesztjeként használjuk. Folyamatos noninvazív vérnyomásméréssel kiegészítve, a manőver a hagyományos kardiális, vagális paraméterek mérése mellett a vazomotorválaszok értékelését is lehetővé teszi. A Müller- manővert többnyire obstruktív alvási apnoés (OSA) epizódok szimulálására végeztetjük. A manőver kiegészítése folyamatos vérnyomás-monitorozással és a szimpatikus izom idegaktivitásának (MSNA) mérésével az alvási apnoe szindróma és az ahhoz társuló cardiovascularis betegségek kapcsolatára derít fényt.