THE world’s smallest cardiac pacemaker was recently implanted in a 74-year-old man by a medical team of the Department of Cardiology of Shenzhen University General Hospital (SUGH).

“With this invisible bodyguard, I feel comfortable in my heart,” the patient identified as Uncle Qiang told Shenzhen Economic Daily.

Uncle Qiang has suffered atrial fibrillation for more than 10 years. The heartbeat for a normal person is 60-100 beats per minute, but Uncle Qiang’s could reach 150-170 beats per minute. The rapid heartbeat made him feel terrible. Palpitation, shortness of breath and repeated coughing often afflicted him, and his feet were swollen like loaves of bread.

Recently, Uncle Qiang was hospitalized in the Department of Cardiology of SUGH. After a series of medical inspections, a doctor found that the concentration of NT-ProBNP, the substance to reflect cardiac function, reached 8,000 picograms per milliliter (pg/ml), which is 10 times higher than a normal person.

Going through several treatments, Uncle Qiang was still severely short of breath and the density of his NT-ProBNP read as high as 4,800 pg/ml. All the treatments and medicine being used were not effective for him.

Li Haiying, the director of cardiology department of SUGH, suggested surgery for him to implant a new capsule-like Micra pacemaker.

A Micra pacemaker is 93 percent smaller than a conventional pacemaker — only 1.75 grams in weight, and about the size of a large vitamin capsule. It is the smallest pacemaker ever recorded in the world, but features a battery that enables the “capsule” to operate in the body for 12 years.

With the pacemaker in a patient’s heart, the heartbeat will return to normal, but he or she should hardly be able to feel it. So the pacemaker can be called an invisible bodyguard.

The night right after the surgery, Uncle Qiang was finally able to lie on his back for the first time. The concentration of NT-ProBNP decreased to 800 pg/ml second day after the surgery and smoothly went down to 300 pg/ml by the seventh day.

After taking anticoagulants for three months, Uncle Qiang will stop taking any medicine.

(Chen Siqi)