Featured Research

from universities, journals, and other organizations

Smokers Seven Times More Likely To Receive Jolt From Heart Devices

Date:
May 8, 2006
Source:
Washington University School of Medicine
Summary:
If some patients with heart disease don't take their doctor's advice to quit smoking, they are probably going to get "shocking" reminders. A study conducted at Washington University School of Medicine in St. Louis found that heart patients who had implanted defibrillators and also smoked were seven times more likely to have the devices jolt their hearts back into normal rhythm than nonsmokers with the devices.

If some patients with heart disease don't take their doctor's advice to quit smoking, they are probably going to get "shocking" reminders. A study conducted at Washington University School of Medicine in St. Louis found that heart patients who had implanted defibrillators and also smoked were seven times more likely to have the devices jolt their hearts back into normal rhythm than nonsmokers with the devices. When the devices fire, it can feel like a thump or even a strong kick to the chest.

Related Articles


"Eleven percent of cardiovascular deaths are related to smoking, and previous studies have shown that decreasing or quitting smoking is in itself a very effective therapy for patients with heart disease," says J. Mauricio Sánchez, M.D., lead author of the study, which was published in the April 2006 issue of Heart Rhythm.

"But if having heart disease isn't enough to make patients want to stop smoking," continues Sánchez, a cardiology fellow in the cardiovascular division, "the evidence from our study should definitely add a strong argument to quit."

Implantable cardioverter-defibrillators (ICDs) are self-contained units that are placed within the chest to monitor heart rhythms and deliver electrical charges directly to heart muscle to correct abnormal rhythms. Abnormal rhythms can occur without warning, and some can cause death rapidly if no action is taken. A recent study demonstrated that ICDs decreased the risk of death by 23 percent in patients with congestive heart failure.

"ICDs are implanted in patients at high risk for sudden cardiac death," Sánchez says. "The devices shock the heart out of dangerous rhythms within seconds after they detect them. It's like having a little ambulance in your chest."

The study looked at 105 patients at the School of Medicine with heart disease who had ICDs implanted to prevent sudden cardiac death. The patients were followed for an average of two years.

During this time, more than a third of the patients who smoked received an electrical discharge from their ICDs to correct a potentially life-threatening heart rhythm. Former smokers, those who had stopped smoking at least a month before the study began, still had a fairly high occurrence of ICD discharge — about a quarter of these patients were shocked by the devices. In contrast, among patients who had never smoked, only about 6 percent received an ICD discharge.

Analysis showed that current smoking generated a seven-fold increased risk for ICD discharge, while having formerly smoked was linked to a five-and-a-half-fold increased risk. The risk of ICD discharge associated with smoking was greater than the risk associated with other factors such as age, diabetes, lung disease or use of ACE inhibitors or beta-blockers.

According to Sánchez, smoking can harm the heart in several ways. One is that nicotine increases the amount of adrenaline, which can lead to blood vessel constriction and decreased blood flow to the heart. Smoking also increases blood clotting factors, which can raise the chance of blood vessel blockage. In addition, the hemoglobin in smokers' blood has carbon monoxide attached to it and can't carry as much oxygen. Both smokers and former smokers have more atherosclerosis in the blood vessels of the heart that lower the oxygen level.

Any of these factors can result in an imbalance of oxygen supply compared to oxygen needed by the heart. This oxygen deficiency predisposes the heart to dangerous rhythms.

"Smoking is obviously hard to quit," Sánchez says. "Heart patients know it's harmful, yet a good percentage of them continue to smoke. It's clear that quitting should be advocated for a whole myriad of reasons, and our study reveals another."

Sánchez JM, Greenberg SL, Chen J, Gleva MJ, Lindsay BD, Smith TW, Faddis MN. Smokers are at markedly increased risk of appropriate defibrillator shocks in a primary prevention population. Heart Rhythm 2006;3(4):443-449.

Several of the authors are consultants for a scientific study/trial for Guidant Corporation and Medtronic Inc.


Story Source:

The above story is based on materials provided by Washington University School of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

Washington University School of Medicine. "Smokers Seven Times More Likely To Receive Jolt From Heart Devices." ScienceDaily. ScienceDaily, 8 May 2006. <www.sciencedaily.com/releases/2006/05/060508165218.htm>.
Washington University School of Medicine. (2006, May 8). Smokers Seven Times More Likely To Receive Jolt From Heart Devices. ScienceDaily. Retrieved November 21, 2014 from www.sciencedaily.com/releases/2006/05/060508165218.htm
Washington University School of Medicine. "Smokers Seven Times More Likely To Receive Jolt From Heart Devices." ScienceDaily. www.sciencedaily.com/releases/2006/05/060508165218.htm (accessed November 21, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Friday, November 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

WFP: Ebola Risks Heightened Among Women Throughout Africa

WFP: Ebola Risks Heightened Among Women Throughout Africa

AFP (Nov. 21, 2014) — Having children has always been a frightening prospect in Sierra Leone, the world's most dangerous place to give birth, but Ebola has presented an alarming new threat for expectant mothers. Duration: 00:37 Video provided by AFP
Powered by NewsLook.com
Could Your Genes Be The Reason You're Single?

Could Your Genes Be The Reason You're Single?

Newsy (Nov. 21, 2014) — Researchers in Beijing discovered a gene called 5-HTA1, and carriers are reportedly 20 percent more likely to be single. Video provided by Newsy
Powered by NewsLook.com
Milestone Birthdays Can Bring Existential Crisis, Study Says

Milestone Birthdays Can Bring Existential Crisis, Study Says

Newsy (Nov. 21, 2014) — Researchers find that as people approach new decades in their lives they make bigger life decisions. Video provided by Newsy
Powered by NewsLook.com
Ebola: Life Without School in Guinea

Ebola: Life Without School in Guinea

AFP (Nov. 21, 2014) — Following the closure of schools and universities in Guinea because of the Ebola virus, students look for temporary work or gather in makeshift classrooms to catch up on their syllabus. Duration: 02:14 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins