Introduction

Definitions

On the basis of the results of observational studies and their meta-analyses 4 circadian BP phenotypes are usually identified, that is (i) dipping: a decrease ≥10% and <20% in mean BP at night compared to mean daytime values; (ii) non-dipping: <10% BP reduction of night-time vs. daytime BP; (iii) reverse dipping: a rise rather than a fall of night-time BP; and (iv) extreme dipping (ED): a night-time BP fall ≥ 20% [3]. The ED pattern was defined as follows: (i) a night time SBP and DBP reduction of both SBP and DBP ≥ 20% compared to daytime values; (ii) a night time SBP reduction ≥ 20% compared to daytime values; (iii) a night time DBP reduction ≥ than 20% compared to daytime values. According to the 2018 European Society Hypertension/European Society Cardiology guidelines, a mean night-time SBP ≥120 mm Hg and/ or DBP ≥ 70 mm Hg is the value dividing nocturnal BP normality from elevation [4]. This, and the data of other specific studies, led to the definition of nocturnal hypotension as a mean SBP < 90 mm Hg and/or DBP < 50 mm Hg [5,6]. In a secondary analysis, mean night-time SBP values < 100 mm Hg and/or DBP values < 60 mm Hg were used [7]. These circadian BP phenotypes have been shown to be associated with different risks of subclinical hypertension mediated organ damage (HMOD), CV ( cardiovascular) outcomes and all-cause mortality [8,9] in ED, an excessive drop in nocturnal BP may potentially trigger cardiac and/or cerebral hypo perfusion and thus vital organ ischemia leading to an increased CV risk [10,11]. A previous meta‐analysis demonstrated that the nocturnal BP values measured by home BP monitoring (HBPM) were similar to those measured by ambulatory BP monitoring (ABPM) and showed a comparable relationship with target organ damage compared to those measured by ABPM, which has been the gold standard for measurement of nocturnal BP levels. A reduction of nocturnal ambulatory BP (ABP) has been linked to cardiovascular protection, and thus, nocturnal home BP (HBP) reduction could be an important strategy for the management of hypertension [12-15].

Case Report

A 91-year-old female presented to our hospital complaining from dizziness and vertigo long time ago with recurrent reviewing the ER with this complain in last months the patient known diabetic type II on oral medication and hypertensive on beta blocker with ACEI. The patient was conscious and oriented. Admitted in the ordinary medical ward as a case of vertigo for more investigations. She was reviewed by ENT consultant 10 days ago and she was free from ENT causes. After the hospital admission CT brain done and released just age related brain atrophy and the patient reviewed by neurology consultant and she reported free from the neurological side. After less than 48 hours from the hospital admission the blood pressure rising up to 180/110 and the patient transferred to ICU as a case of hypertensive urgency for close monitoring and blood pressure control. In ICU, we noticed that the blood pressure markedly dropped during night-time reached up to 80/40 and in the morning the blood pressure rising again with increasing the dizziness and vertigo in the early morning. In the ICU, the blood pressure was controlled initially by intravenous medication (nitro-glycerine) then it is stopped and the blood pressure controlled on oral medications (amlodipine, aldomet, valsartan and bisoprolol) but the blood pressure still fluctuating (rising during day time and dropped during night-time). After that the oral antihypertensive medications changed to long acting calcium channel blocker (nifidpin 90 mg once daily oral) after that the blood pressure controlled all over the time with marked improvement in the neurogenic symptoms, dizziness and vertigo. The patient transferred from ICU to the ordinary medical ward then discharged home in good condition.

Discussion

Nocturnal hypotension is a rare condition associated with cardiovascular target organ damage and cardiovascular mortality in hypertensive patients. Abnormal circadian blood pressure patterns associated with elevated sleep blood pressure include no dipping and reverse dipping, both of which are associated with increased target-organ damage and adverse cardiovascular outcomes. Although nocturnal hypotension is considered the key factor responsible for the increased cardiovascular risk associated with the extreme dipping (ED) pattern, no information is available on its prevalence in this setting. In a previous study A total of 7,074 individuals 24-hour ambulatory BP recordings (ABPM) from untreated individuals with a history of hypertension and treated hypertensive individuals referred to a single out-patient hypertension centre (Clinical Research Unit Meda, institute Auxologico Italiano and University of Milano-Bicocca) by their general practitioners during a 5-year period (November 2013 to December 2018) were analysed. Individuals aged <18 years, with suboptimal ABPM recordings (<70 % successful readings) or doing shift work were excluded from data analysis. Of those patients, 61% exhibited a nocturnal decline ≥20% in both SBP and DBP. In the remaining 39% patients, a decline ≥20% was limited to only DBP, whereas no subject showed an excessive decline of SBP only. In the total sample, prevalence rates of nocturnal hypotension (i.e., mean night-time SBP <90 mm Hg and/or DBP < 50 mm Hg) were 9.1% [16].