Docstoc

Device-assisted Slow Breathing as a Complementary Treatment for

Document Sample
Device-assisted Slow Breathing as a Complementary Treatment for Powered By Docstoc
					                                                                           hypertension                             Canada 3

Device-assisted Slow Breathing as a
Complementary Treatment for
Hypertension
By Robert P. Nolan                              breathing has not been clearly demon-           Parati and Carretta in the Journal of Hy-
Guidelines for primary and secondary            strated.                                        pertension in 2007 summarized the
prevention of cardiovascular disease in            Device-assisted training in slow breath-     available evidence on RESPeRATE as
Europe and North America suggest                ing with the RESPeRATE apparatus has            consisting of one review paper with a case
that behavioral interventions (relax-           been reported to reduce BP of hyperten-         study, two small sample observational
ation training, stress management,              sive subjects with or without antihyper-        studies with a pre- and post-treatment
biofeedback or meditation) may assist           tensive medication, following eight weeks       comparison, two prospective investiga-
the treatment of patients for whom              of treatment that included 10 to 15 min-        tions that utilized a case-control design,
psychosocial stress is of clinical con-         utes of practice per day. The RESPeRATE         and two randomized controlled trials.
cern. Several reviews have evaluated            intervention consists of a thoracic belt that   One of the latter two randomized trials di-
whether these behavioral interventions
can be utilized to improve the regula-
tion of blood pressure (BP) among pa-
                                                   Device-assisted training in slow breathing with the RESPeRATE
tients with hypertension. With the              apparatus has been reported to reduce BP of hypertensive subjects
exception of smoking cessation, exer-           with or without antihypertensive medication, following eight weeks
cise training and diet modification, no
behavioral treatment has been estab-
                                                    of treatment that included 10 to 15 minutes of practice per day.
lished as conferring independent bene-
fit on long-term clinical outcomes,
including BP reduction.                         monitors chest movement associated with         rected an “active” control group to listen
   Over the past 15 years there has been        respiration. This signal is analyzed by a       to synthesized tones (similar to RESPeR-
considerable research regarding a po-           control unit that plays back (in real time,     ATE) for a 10-minute interval each day on
tential antihypertensive effect of slow,        via headphones) synthesized musical             portable audio players. This procedure
deep breathing, which is a common fea-          tones for inspiration and expiration match-     may have been viewed with some skepti-
ture of behavioral training in stress-          ing the patient’s breathing pattern. The        cism, as evidenced by the 12% dropout
reduction techniques. Paced breathing,          control unit gradually prolongs the expira-     rate in this study that arose solely from
between six and 10 breaths per minute,          tion phase of breathing and the patient is      control subjects. The other randomized
has been reported to evoke short-term           directed to follow the modified sound pat-      trial used a control condition in which pa-
reductions in systolic and diastolic BP         tern within their comfort range until a         tients simply monitored their BP.
among patients with hypertension, car-          steady state is obtained, which is targeted        There has not been a lot of critical dis-
diovascular disease and chronic heart           below 10 breaths per minute.                    cussion in the available literature about
failure.                                           The RESPeRATE website (www.res-              the RESPeRATE treatment, perhaps be-
   It is hypothesized that slow, deep breath-   perate.com) states that systolic and            cause almost all of the small number of
ing as a complementary antihypertensive         diastolic BP of hypertensive patients           published reports were at least partially
treatment augments vagal-efferent modu-         is reduced on average by 14 mmHg to             affiliated with the manufacturer. How-
lation of heart rate, while increasing car-     8 mmHg. This estimate is based on               ever this situation changed in 2007 with
diovagal baroreflex control over BP and         seven studies, all with positive findings,      the publication of a clinical trial by
sympathetic outflow to peripheral sites,        derived from a pooled sample of 256 pa-         Logtenberg et al in the Journal of Hy-
which decreases peripheral resistance.          tients. The website promotes it as a safe       pertension that prompted the above-
However, a specific depressor mechanism         treatment for patients with diabetes and        noted editorial review (Parati and
that is linked to treatment with slow, deep     kidney failure. An editorial review by          Carretta 2007). This randomized con-
                                                                                                                       continued on page 8
8 hypertension Canada
                                                                                                Further Reading:
Hypertension in Children                       ingful clinical trial endpoints and dose-        1. The Fourth Report on the Diagnosis, Evaluation and
                                                                                                    Treatment of High Blood Pressure in Children and
Continued from page 5                          response effects, and the paucity of                 Adolescents. Pediatrics 2004; 114: 555-76.
                                               large trials using superior design strate-           Avaliable at: http://pediatrics.aappublications.org/
                                                                                                    cgi/content/full/114/2/S2/555. Accessed May 2008.
BP-reduction, which was slightly               gies. Future studies should link the ef-         2. Simonetti GD Rizzi M, Donadini R, Bianchetti MG.
greater with ARBs than with CCBs. As           fect of antihypertensive drugs to target             Effects of antihypertensive drugs on blood pressure
                                                                                                    and proteinuria in childhood. J Hypertens 2007;
expected from the mechanism of ac-             organ damage and ultimate patient out-               25: 2370-76.
tion, the ACE inhibitors and ARBs sig-         comes. Meanwhile, clinicians caring              3. Benjamin DK, Smith PB, Jadhav P et al. Pediatric
                                                                                                    Antihypertensive Trial Failures. Analysis of end
nificantly reduced proteinuria by 49%          for children are forced to extrapolate               points and dose range. J Hypertens 2008; 51: 834-40
and 59%, respectively.                         from the large body of evidence among
                                               adult subjects, which suggests that re-          Susan Koshy, MSc, MD, FRCPC; Silviu
Conclusions                                    duction in BP is associated with im-             Grisaru, MD; and Julian Midgley, BM
Our clinical knowledge is limited by           proved overall cardiovascular health             BCh, DCH, FRCPC, Division of
the rarity of hypertension in children,        and survival.                                    Pediatric Nephrology, Alberta
making it difficult to observe mean-                                                            Children’s Hospital, Calgary, Alberta.




Device-assisted Breathing
Continued from page 3                          1. The absence of an appropriate                pelling evidence seems warranted be-
                                                  intention-to-treat analysis, where the       fore it can be widely recommended to
trolled trial enrolled patients with hyper-       BP measures of dropouts should               patients as a complementary treatment
tension and a diagnosis (> 2 years) of            have been incorporated into the              that offers additional, independent ben-
type 2 diabetes. All were receiving anti-         outcome data; and                            efit for BP reduction.
hypertensive medications, which were           2. Use of an “active” control procedure
not altered. RESPeRATE was compared               that is appropriately matched to
to an active control group that listened to       RESPeRATE and which is plausible
                                                                                               Further Reading:
diverse types of music under the auspices         to subjects as a behavioral                  1. Chacko NJ, Porta C, Casucci G et al. Slow breathing
of “music therapy.” Outcome following             antihypertensive procedure.                      improves arterial baroreflex sensitivity and de-
eight weeks of treatment was evaluated           Certainly, it is important to resolve             creases blood pressure in essential hypertension.
                                                                                                   J Hypertens 2005; 46: 714-8.
using an intention-to-treat analysis. Of       these issues before RESPeRATE can               2. Logtenberg SL, Kleefstra N, Houweling ST et al. Effect
note, systolic/diastolic BP at post-treat-     be viewed as an independent, comple-                of a device-guided breathing exercises on blood
                                                                                                   pressure in hypertensive patients with type 2
ment was reduced in the RESPeRATE              mentary treatment for hypertension.                 diabetes mellitus: a randomized controlled trial.
group (-7.5 mmHg/-1.0 mmHg) and                  In summary, slow and paced breathing              J Hypertens 2007; 25: 241-6.
                                                                                               3. Parati G, Carretta R. Device-guided slow breathing
controls (-12.2 mmHg/ -5.5 mmHg). The          may prove to be a critical component of             as a non-pharmacological approach to anti-
magnitude of BP reduction did not differ       behavioral interventions (e.g., relaxation          hypertensive treatment: efficacy, problems and
                                                                                                   perspectives. J Hypertens 2007; 25: 57-61.
between these two groups.                      training, meditation and biofeedback)
   The report of a null finding for the        that evoke short-term reductions in BP.
RESPeRATE device helped to promote a           Training with the RESPeRATE device
constructive debate in a subsequent ex-        offers a novel approach within this             Robert P. Nolan, PhD, C.Psych,
change of letters about strengths and lim-     class of behavioral procedures. How-            Behavioural Cardiology Research Unit,
itations of this proposed antihypertensive     ever, it is difficult to view the available     University Health Network,
treatment. At least two major shortcom-        evidence concerning RESPeRATE as                Institute of Medical Sciences and
ings are evident in previous research with     having evolved beyond an experimen-             Department of Psychiatry,
RESPeRATE:                                     tal stage of development. More com-             University of Toronto.



 Readers of Hypertension Canada are invited to visit the CHS homepage at www.hypertension.ca/chs and submit suggestions on its improvement.
       Hypertension
       Canada                    is published by the Canadian      Hypertension Society

				
DOCUMENT INFO