Oral and intravenous hydration in the treatment of orthostatic hypotension and postural tachycardia syndrome

Hydration with water and salt is the mainstay of treatment for autonomic nervous system disorders that impair orthostatic tolerance. The goal is to expand intravascular volume to compensate for the downward displacement of blood volume that occurs when standing and thereby sustain cerebral perfusion and restore quality of life. Despite strong consensus recommendations for salt supplementation as standard treatment of these disorders, published evidence of benefit is relatively weak, and no randomized clinical trials have occurred. This review summarizes the physiological rationale for hydration and evaluates the literature on oral and intravenous hydration in the treatment of neurogenic orthostatic hypotension, postural tachycardia syndrome, and recurrent vasovagal syncope. We conclude that oral salt replacement is indicated for treatment of neurogenic orthostatic hypotension because these patients have excessive renal sodium excretion, and for treatment of chronic orthostatic intolerance because these patients are often hypovolemic. As not all patients are able to tolerate sufficient oral hydration, there is also a role for intravenous volume-loading in severe cases of postural tachycardia syndrome. We offer guidance, based on review of the literature and the clinical judgment of a cardiologist and neurologist with experience treating autonomic disorders, regarding the option of ongoing intravenous hydration for treatment of severe, refractory cases of postural tachycardia syndrome.

Safety in dermatologic procedures: anaphylaxis, vasovagal reaction, and hyperventilation

This article, part of a the series on safety in dermatologic procedures, covers the diagnosis, prevention, management, and treatment of 3 situations or conditions. The first condition we address is anaphylaxis, an uncommon but severe and potentially fatal reaction that must be recognized quickly so that urgent management coordinated with an anesthesiologist can commence. The second is fainting due to a vasovagal reaction, which is the most common complication in dermatologic surgery. This event, which occurs in 1 out of every 160 procedures, usually follows a benign course and resolves on its own. However, in patients susceptible to vasovagal reactions, syncope may lead to asystole and cardiac arrest. The third is acute hyperventilation syndrome, which is an anomalous anxiety-related increase in breathing rate beyond metabolic requirements. Brief practical recommendations for managing all 3 events are included.

[Syncope]

Syncope is a frequent disorder, sometimes due to life-threatening causes. The uncertainty in its diagnosis requires a standardized approach. According to the 2018 European Society of Cardiology (ESC) guidelines, new aspects in evaluation and treatment include risk stratification and decision-making strategies during the initial evaluation in the emergency department, a reconsideration of diagnostic tests, algorithms for the treatment of reflex syncope, indications for an implantable cardioverter/defibrillator in high risk patients for sudden cardiac death, and organizational aspects such as interdisciplinary syncope units. The 2018 ESC guideline and the 2019 commentaries of the German Society of Cardiology (DGK) are an excellent and comprehensive instruction for safe, effective and efficient evaluation and therapy. However, some aspects require critical appraisal. The inadequate availability and reimbursement of pivotal diagnostic tests, such as tilt table testing and the implantable loop recorder is emphasized.

Nitrates and risk of vasovagal reaction in femoral sheath removal after percutaneous intervention : A retrospective observational study

BACKGROUND

The aim of this study was to analyze the risk factors for vasovagal reaction (VVR) in manual femoral sheath removal after percutaneous coronary intervention and to discuss methods for the prevention and control of VVR.

METHODS

The data of 455 patients who underwent percutaneous intervention in four interventional centers during a period of 30 months were retrospectively analyzed. Patients were divided into a VVR group and a control group according to whether VVR developed. The clinical data of all patients were analyzed using univariate and multivariate logistic regression analysis to examine VVR -related factors.

RESULTS

A total of 455 patients underwent 464 manual femoral sheath removal operations, of whom 12 developed VVR (2.59%). Of these 12 VVR patients, one had VVR during and 11 had VVR after the intervention. There were no statistically significant differences between the two groups in age, body mass index, gender, time of sheath removal, proportions of patients with hypertension, diabetes, and hyperlipemia, laboratory values of hemoglobin a1c, and ejection fraction (p > 0.05). Compared with the control group, use of nitrates was the only risk factor with a significant correlation with VVR (p = 0.012).

CONCLUSION

In manual femoral sheath removal, the use of nitrates is the most important risk factor for the occurrence of VVR after percutaneous intervention.

Heart rate recovery and diastolic blood pressure ratio on the treadmill test predict an induction and recurrence of vasovagal syncope

BACKGROUND/AIMS

The induction and recurrence of syncope is a concerning situation that could be unpredicted in the vasovagal syncope (VVS). We investigated a simple predictor for the induced and recurrent VVS during Head-Up table-tilt Test (HUT) and clinically follow-up.

METHODS

The 143 consecutive patients with VVS (age 31 ± 19 years, 33 male) who referred by a cardiologist or neurologist and had undergone an echocardiogram, HUT, and a treadmill exercise test (TMT) were recruited and clinically follow-up. Patients were divided into two groups based on the result of HUT and TMT. The data was analyzed and compared between VVS patients and control 141 patients without VVS who were enrolled in the same study period (age 40 ± 5 years, 117 male).

RESULTS

The heart rate recovery (HRR), recovery systolic blood pressure (RecSBP), recovery diastolic blood pressure (RecDBP), HRR/RecSBP and HRR/RecDBP were significantly different between controls and VVS during the TMT. Within VVS, even if, baseline characteristics were similar between negative and positive HUT (n = 92 vs. n = 51). HRR (31 ± 10 vs. 35 ± 10), HRR/RecSBP (0.24 ± 0.09 vs. 0.28 ± 0.09) and HRR/RecDBP (0.49 ± 0.18 vs. 0.58 ± 0.19) were significantly different between negative and positive HUT results. Especially, HRR/RecSBP and HRR/RecDBP were significantly correlated with induced syncope with a sensitivity and specificity ([60%, 83%] cut-off, 0.31; [72%, 80%] cut-off, 0.63). In the Cox regression, HRR/ RecDBP were significantly associated with recurrence of VVS with hazard ratio of 3.29 (confidence interval, 0.95 to 11.3; p = 0.049).

CONCLUSION

HRR/RecDBP may be a useful predictor for induction during HUT and recurrence during follow-up in the VVS.

[Association between C1114G polymorphism in the regulator of G protein signaling 2 and vasovagal syncope in children]

Objective: To analyze the distribution of the regulator of G protein signaling 2 (RGS2) gene C1114G polymorphism in children with vasovagal syncope (VVS) and the associated clinical classification groups, and to explore the association between RGS2 C1114G and VVS. Methods: This was a prospective case-control study. A head-up tilt test (HUT) was performed in 300 children visiting Children's Hospital Affiliated to Shanghai Jiaotong University from August 2010 to December 2015 for unexplained syncope. A total of 150 children with positive HUT and a diagnosis of VVS were enrolled and assigned to the VVS group. The VVS group was further divided into 3 subgroups based on characteristics of the heart rate and blood pressure measured during the HUT. A total of 150 children with negative HUT were enrolled and assigned to the HUT-negative group. A total of 150 healthy children were enrolled as the normal control group for genetic polymorphism detection. The clinical characteristics of patients in the VVS group and the HUT-negative group were recorded. Peripheral blood samples of each case were collected. RGS2 C1114G polymorphism was evaluated using high-resolution melting curve and polymerase chain reaction together with gene sequencing. The genotype and allele frequency were analyzed and compared among different groups (VVS, HUT-negative, and normal control) and VVS subgroups. Comparisons among groups were performed using Chi-square test. Results: Patients in the VVS group (48 males and 102 females, aged (10.1±3.2) years) were more frequently female (68.0% vs. 57.3%;χ(2)=5.090, P=0.024) compared with patients in the HUT-negative group (67 males and 83 females, aged (10.8±2.2) years). No significant difference was found regarding the distribution of the CC genotype, CG genotype and GG genotype among the VVS group (n=98, 65.3%; n=36, 24.0%; n=16, 10.7%), the HUT-negative group (n=112, 74.7%; n=28, 18.7%; n=10, 6.7%) and the normal control group (n=108, 72.0%; n=31, 20.7%; n=11, 7.3%) (χ(2)=3.632, P=0.458). There was no significant difference in the frequencies of C allele and G allele in the VVS group (n=232, 77.3%; n=68, 22.7%), the HUT-negative group (n=252, 84.0%; n=48,16.0%) and the normal control group (n=247, 82.3%; n=53, 17.7%) (χ(2)=4.659, P=0.097). The 150 children in the VVS group were further divided into the mixed-response subgroup (n=83), vasodepressor-response subgroup (n=42) and cardioinhibitory-response subgroup (n=25). The CC genotype, CG genotype and GG genotype in the mixed-response subgroup, the vasodepressor-response subgroup and the cardioinhibitory-response subgroup were (n=65, 78.3%; n=16, 19.3%; n=2, 2.4%), (n=20, 47.6%; n=11, 26.2%; n=11, 26.2%) and (n=13, 52.0%; n=9, 36.0%; n=3, 12.0%), respectively. The frequencies of C allele and G allele in the mixed-response subgroup, the vasodepressor-response subgroup, and the cardioinhibitory-response subgroup were (n=146, 88.0%; n=20, 12.0%), (n=51, 60.7%; n=33, 39.3%) and (n=35, 70.0%; n=15, 30.0%), respectively. The percentages of the GG genotype and G allele were significantly higher in the vasodepressor-response subgroup than the other two subgroups (χ(2)=21.698, 25.345, all P=0.000). Conclusions: No significant association was found between RGS2 C1114G polymorphism and VVS in children. Due to the higher distribution of GG genotype and G allele in the vasopressor-response subgroup, RGS2 C1114G may be associated with the regulation of blood pressure during the onset of VVS in children.

Positive result in the early passive phase of the tilt-table test: a predictor of neurocardiogenic syncope in young men

BACKGROUND/AIMS

This study elucidated the prognostic factors for neurocardiogenic syncope in males in their late teens and early twenties.

METHODS

Tilt-table testing (TTT) was performed on 665 males (age range, 17 to 27 years) following the Italian protocol. The subjects were tilted head-up at a 70° angle on a table for 30 minutes during the passive phase. If the passive phase was negative, the subjects were given sublingual nitroglycerin and tilted to the same angle for 20 minutes during the drug-provocation phase. The subjects with positive results were followed without medication. We analyzed factors related to the recurrence rate of syncope.

RESULTS

Of 305 subjects (45.8%) with positive results, 223 (age range, 18 to 26 years) were followed for 12 months. The frequency of previous syncopal episodes ≥ 4 (p = 0.001) and a positive result during the passive phase (p = 0.022) were significantly related to a high recurrence rate. A positive result during the early passive phase (≤ 12 minutes) was significantly related to a higher recurrence rate than was that during the late passive phase (> 12 minutes; p = 0.011).

CONCLUSIONS

A positive result during the early passive phase of TTT and frequent previous syncopal episodes were prognostic factors for neurocardiogenic syncope in men in their late teens and early twenties.

Comparison of recurrence rate based on the frequency of preceding symptoms in patients with neurocardiogenic syncope or presyncope

BACKGROUND AND OBJECTIVES

In patients with neurocardiogenic syncope or presyncope, symptoms developed unpredictably and intermittently. The purpose of this study was to determine whether there was any significant difference in the recurrence rate of symptoms during the follow-up period between patients with many episodes of symptoms and those with fewer episodes of symptoms before diagnosis, as well as to assess the clinical significance of previous episodes of symptoms during treatment.

SUBJECTS AND METHODS

A total of 100 patients with neurocardiogenic syncope or presyncope were divided in two groups (high episode group, n=54; low episode group, n=46) according to the frequency of symptoms before the head-up tilt test. We retrospectively analyzed the recurrence of symptoms using telephone interviews and medical record reviews.

RESULTS

The clinical characteristics were not significantly different between the two groups. However, the recurrence rate was significantly lower in the high episode group than in the low episode group (5.6% vs. 19.6%, p=0.001). In the high episode group, patients treated with medication showed higher recurrence of symptoms than those without medication. In the lower episode group, a similar result was observed.

CONCLUSION

The frequency of previous symptoms at the diagnosis of neurocardiogenic syncope or presyncope did not predict the occurrence of symptoms during the follow-up period. Therefore, to continue drug treatment based on the frequency of symptoms in patients with neurocardiogenic syncope or presyncope may not be the best option.